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Cai, Yingxiang, Jiamin Xiong, Yabo Liu i Xuechun Xu. "Electronic structure and chemical hydrogen storage of a porous sp3 tetragonal BC2N compound". Journal of Alloys and Compounds 724 (listopad 2017): 229–33. http://dx.doi.org/10.1016/j.jallcom.2017.06.343.
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Szarek, Pawel, Kouhei Watanabe, Kazuhide Ichikawa i Akitomo Tachibana. "Electronic Stress Tensor Study of Aluminum Nanostructures for Hydrogen Storage". Materials Science Forum 638-642 (styczeń 2010): 1137–42. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.1137.
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We report the new structures of aluminum hydrides derived from the Al4 tetrahedral cages. We perform ab initio quantum chemical calculation for these new aluminum hydrides. Our calculation of binding energies of the new aluminum hydrides reveal that stability of these hydrides increases as more hydrogen atoms are adsorbed, while stability of Al-H bonds decreases. We also calculate electronic stress tensor to evaluate the chemical bonds of these hydrides. As a result, we find that the bonds of the Al4 tetrahedral cage are strengthened as more hydrogen atoms are adsorbed on the aluminum hydrides. Our calculation of the potential energy surfaces and the regional chemical potential show that hydrogen atoms are likely to adsorb on bridge site at first.
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Ichikawa, Kazuhide, Yuji Ikeda, Ryo Terashima i Akitomo Tachibana. "Aluminum Hydride Clusters as Hydrogen Storage Materials and their Electronic Stress Tensor Analysis". Materials Science Forum 706-709 (styczeń 2012): 1539–44. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.1539.
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We study the chemical bonds of small Al clusters (Aln, n=2-8) and hydrogenated Al clusters (AlnHm , n=1-8 and m=1,2) using electronic stress tensor. We calculate the bond order based on energy density for these clusters. We also study the electronic structure under the presence of electronic current by the electronic stress tensor for AlH3 molecule.
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Morinaga, Masahiko, i Hiroshi Yukawa. "Characteristics of Electronic Structures and Chemical Bonding in Hydrogen-Storage Compounds". Materials Science Forum 426-432 (sierpień 2003): 2237–42. http://dx.doi.org/10.4028/www.scientific.net/msf.426-432.2237.
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Seo, Okkyun, Jaemyung Kim, Akhil Tayal, Chulho Song, L. S. R. Kumara, Shun Dekura, Hirokazu Kobayashi, Hiroshi Kitagawa i Osami Sakata. "The relationship between crystalline disorder and electronic structure of Pd nanoparticles and their hydrogen storage properties". RSC Advances 9, nr 37 (2019): 21311–17. http://dx.doi.org/10.1039/c9ra02942g.
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Smaller Pd nanoparticles have a high degree of disordering and a lower coordination number on the surface part, which causes a change in electronic structure to have different hydrogen storage properties.
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Cui, Hong, Ying Zhang, Weizhi Tian, Yazhou Wang, Tong Liu, Yunjian Chen, Pengyue Shan i Hongkuan Yuan. "A study on hydrogen storage performance of Ti decorated vacancies graphene structure on the first principle". RSC Advances 11, nr 23 (2021): 13912–18. http://dx.doi.org/10.1039/d1ra00214g.
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Gao, Peng, Zonghang Liu, Jiefeng Diao, Jiaao Wang, Jiwen Li, Yuebin Tan, Guangtong Hai i Graeme Henkelman. "Calculated Outstanding Energy-Storage Media by Aluminum-Decorated Carbon Nitride (g-C3N4): Elucidating the Synergistic Effects of Electronic Structure Tuning and Localized Electron Redistribution". Crystals 13, nr 4 (11.04.2023): 655. http://dx.doi.org/10.3390/cryst13040655.
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Hydrogen, as an important clean energy source, is difficult to store and transport, which hinders its applications in real practice. Developing robust yet affordable storage media remains to be a challenge for scientists. In this study, Ab Initio Molecular Dynamics (AIMD) simulations were employed to evaluate the performance of aluminum (Al) decorated carbon nitride (g-C3N4, heptazine structure) in hydrogen storage; and a benchmarking study with Mg-doped g-C3N4 was also performed to provide theoretical insights for future study. We found that each 2 × 2 supercell can accommodate four Al atoms, and that partial charge from single Al sites can be transferred to adjacent nitrogen atoms of g-C3N4. These isolated Al sites tend to be electronically positive charged, serving as active sites for H2 adsorption, predominately by triggering enhanced electrostatic interactions. The H2 molecules are adsorbed by both Al and N atoms, and are easily polarized, giving rise to electrostatic interactions between the gas molecules and the surface. Effective adsorption sites were determined by electronic potential distribution maps of the optimized configurations. Each 2 × 2 supercell can adsorb up to 36 H2 molecules, and the corresponding adsorption energies are within the range of −0.10 to −0.26 eV. The H2 storage capacity of the Al-decorated g-C3N4 is 7.86 wt%, which surpasses the goal of 5.5 wt%, set by the US department of energy. This proposed Al-decorated g-C3N4 material is therefore predicted to be efficient for hydrogen storage. This work may offer some fundamental understandings from the aspect of electronic sharing paradigm of the origin of the excellent hydrogen storage performance by metal decorated 2D materials, acting as an demonstration for guiding single metal atom site-based materials’ designing and synthesis.
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Zhang, Jun-Jun, Meng-Yang Li, Xiang Li, Wei-Wei Bao, Chang-Qing Jin, Xiao-Hua Feng, Ge Liu, Chun-Ming Yang i Nan-Nan Zhang. "Chromium-Modified Ultrathin CoFe LDH as High-Efficiency Electrode for Hydrogen Evolution Reaction". Nanomaterials 12, nr 7 (6.04.2022): 1227. http://dx.doi.org/10.3390/nano12071227.
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Hydrogen evolution reaction (HER) has a dominant function in energy conversion and storage because it supplies a most effective way for converting electricity into sustainable high-purity hydrogen. Layered double hydroxides (LDHs) have shown promising performance in the process of electrochemical water oxidation (a half-reaction for water splitting). Nevertheless, HER properties have not been well released due to the structural characteristics of related materials. Herein, a simple and scalable tactics is developed to synthesize chromium-doped CoFe LDH (CoFeCr LDH). Thanks to oxygen vacancy, optimized electronic structure and interconnected array hierarchical structure, our developed ternary CoFeCr-based layered double hydroxide catalysts can provide 10 mA cm−2 current density at −0.201 V vs. RHE with superior long-term stability in alkaline electrolyte. We anticipate that the simple but feasible polymetallic electronic modulation strategy can strengthen the electrocatalytic property of the layered double hydroxides established in the present study, based on a carbon neutral and hydrogen economy.
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Gao, Peng, Xihao Chen, Jiwen Li, Yue Wang, Ya Liao, Shichang Liao, Guangyu Zhu, Yuebin Tan i Fuqiang Zhai. "Computational Evaluation of Al-Decorated g-CN Nanostructures as High-Performance Hydrogen-Storage Media". Nanomaterials 12, nr 15 (27.07.2022): 2580. http://dx.doi.org/10.3390/nano12152580.
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Density functional theory (DFT) calculations were employed to solve the electronic structure of aluminum (Al)-doped g-CN and further to evaluate its performance in hydrogen storage. Within our configurations, each 2 × 2 supercell of this two-dimensional material can accommodate four Al atoms, and there exist chemical bonding and partial charge transfer between pyridinic nitrogen (N) and Al atoms. The doped Al atom loses electrons and tends to be electronically positive; moreover, a local electronic field can be formed around itself, inducing the adsorbed H2 molecules to be polarized. The polarized H2 molecules were found to be adsorbed by both the N and Al atoms, giving rise to the electrostatic attractions between the H2 molecules and the Al-doped g-CN surface. We found that each 2 × 2 supercell can adsorb at most, 24 H2 molecules, and the corresponding adsorption energies ranged from −0.11 to −0.31 eV. The highest hydrogen-storage capacity of the Al-doped g-CN can reach up to 6.15 wt%, surpassing the goal of 5.50 wt% proposed by the U.S. Department of Energy. Additionally, effective adsorption sites can be easily differentiated by the electronic potential distribution map of the optimized configurations. Such a composite material has been proven to possess a high potential for hydrogen storage, and we have good reasons to expect that in the future, more advanced materials can be developed based on this unit.
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Skryabina, N. E., Vladimir M. Pinyugzhanin i Daniel Fruchart. "Relationship between Micro-/Nano-Structure and Stress Development in TM-Doped Mg-Based Alloys Absorbing Hydrogen". Solid State Phenomena 194 (listopad 2012): 237–44. http://dx.doi.org/10.4028/www.scientific.net/ssp.194.237.
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In the most recent years, MgH2has attracted considerable attention for reversible hydrogen storage purposes because of a large 7.6 w% H-uptake, single plateau reaction at low pressure and abundance of metal. If the Mg ↔ H reactions take place at rather high temperature (> 300°C), the kinetic remains very low. However, early transition metal based additives (Ti, V, Nb...) improve dramatically the kinetics of hydrogen absorption/desorption, while having no essential impact on the reversible sorption capacity. Systematic analysis of many experimental data led to question chemical, physical, mechanical... parameters contributing significantly to improve the kinetics of absorption/desorption. Besides, results of theoretical and numerical computation enlighten the impact of structural and mechanical parameters owing to the local bonds of Mg/MgH2with of TM elements, in terms of total energy and electronic structure. More specifically, we found highly relevant to consider 1 - the impact of the crystallite sizes of Mg and the TM-phase, 2 - the role of internal and external stresses, as well as 3 - the role of texture on the kinetics of hydrogen absorption/desorption. Apart the previous considerations, we like to underline the role of specific TM in trapping intermediately hydrogen thus forming TMHxprior initiating the Mg ↔ MgH2nucleation process.
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Uliasz-Misiak, Barbara, Joanna Lewandowska-Śmierzchalska, Rafał Matuła i Radosław Tarkowski. "Prospects for the Implementation of Underground Hydrogen Storage in the EU". Energies 15, nr 24 (15.12.2022): 9535. http://dx.doi.org/10.3390/en15249535.
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The hydrogen economy is one of the possible directions of development for the European Union economy, which in the perspective of 2050, can ensure climate neutrality for the member states. The use of hydrogen in the economy on a larger scale requires the creation of a storage system. Due to the necessary volumes, the best sites for storage are geological structures (salt caverns, oil and gas deposits or aquifers). This article presents an analysis of prospects for large-scale underground hydrogen storage in geological structures. The political conditions for the implementation of the hydrogen economy in the EU Member States were analysed. The European Commission in its documents (e.g., Green Deal) indicates hydrogen as one of the important elements enabling the implementation of a climate-neutral economy. From the perspective of 2050, the analysis of changes and the forecast of energy consumption in the EU indicate an increase in electricity consumption. The expected increase in the production of energy from renewable sources may contribute to an increase in the production of hydrogen and its role in the economy. From the perspective of 2050, discussed gas should replace natural gas in the chemical, metallurgical and transport industries. In the longer term, the same process will also be observed in the aviation and maritime sectors. Growing charges for CO2 emissions will also contribute to the development of underground hydrogen storage technology. Geological conditions, especially wide-spread aquifers and salt deposits allow the development of underground hydrogen storage in Europe.
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Ao, Rui, Ruihua Lu, Guanghui Leng, Youran Zhu, Fuwu Yan i Qinghua Yu. "A Review on Numerical Simulation of Hydrogen Production from Ammonia Decomposition". Energies 16, nr 2 (13.01.2023): 921. http://dx.doi.org/10.3390/en16020921.
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Ammonia (NH3) is regarded as a promising medium of hydrogen storage, due to its large hydrogen storage density, decent performance on safety and moderate storage conditions. On the user side, NH3 is generally required to decompose into hydrogen for utilization in fuel cells, and therefore it is vital for the NH3-based hydrogen storage technology development to study NH3 decomposition processes and improve the decomposition efficiency. Numerical simulation has become a powerful tool for analyzing the NH3 decomposition processes since it can provide a revealing insight into the heat and mass transfer phenomena and substantial guidance on further improving the decomposition efficiency. This paper reviews the numerical simulations of NH3 decomposition in various application scenarios, including NH3 decomposition in microreactors, coupled combustion chemical reactors, solid oxide fuel cells, and membrane reactors. The models of NH3 decomposition reactions in various scenarios and the heat and mass transport in the reactor are elaborated. The effects of reactor structure and operating conditions on the performance of NH3 decomposition reactor are analyzed. It can be found that NH3 decomposition in microchannel reactors is not limited by heat and mass transfer, and NH3 conversion can be improved by using membrane reactors under the same conditions. Finally, research prospects and opportunities are proposed in terms of model development and reactor performance improvement for NH3 decomposition.
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Maitra, S., R. Mitra i T. K. Nath. "Aqueous Mg-Ion Supercapacitor and Bi-Functional Electrocatalyst Based on MgTiO3 Nanoparticles". Journal of Nanoscience and Nanotechnology 21, nr 12 (1.12.2021): 6217–26. http://dx.doi.org/10.1166/jnn.2021.19321.
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Supercapacitor and hydrogen-based fuel cells are cheap and environmental-friendly next-generation energy storage devices that are intended to replace Lithium-ion batteries. Metal oxide nanostructures having perovskite crystal structure have been found to exhibit unique electrochemical properties owing to its unique electronic band structure and multiple redox-active ions. Herein, MgTiO3 nanoparticles (MTO-1) were synthesized by wet-chemical sol–gel technique with an average particle size of 50–55 nm, which exhibited superior supercapacitor performance of capacitance (C) = 25 F/g (at 0.25 A/g), energy density (ED) = 17 Wh/kg, power density (PD) = 275 W/kg and 82.41% capacitance retention (after 1000 cycles). Aqueous 1 M Mg(ClO4)2 solution was used as the electrolyte. MTO-1 revealed an overpotential (η) = 1.329 V and Tafel slope (b) = 374 mV/dec towards Oxygen Evolution Reaction (OER) electrocatalyst and exhibited η = 0.914 V and b = 301.4 mV/dec towards Hydrogen Evolution Reaction (HER) electrocatalyst, both in presence of alkaline 1 M KOH solution, making these MgTiO3 nanoparticles very promising for potential use in various technologically important electrochemical applications.
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Dixon, David A., i Maciej Gutowski. "Thermodynamic Properties of Molecular Borane Amines and the [BH4-][NH4+] Salt for Chemical Hydrogen Storage Systems from ab Initio Electronic Structure Theory". Journal of Physical Chemistry A 109, nr 23 (czerwiec 2005): 5129–35. http://dx.doi.org/10.1021/jp0445627.
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Chen, J. "Hydrogen Storage Alloys with PuNi[sub 3]-Type Structure as Metal Hydride Electrodes". Electrochemical and Solid-State Letters 3, nr 6 (1999): 249. http://dx.doi.org/10.1149/1.1391115.
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Ni, Chunsheng, Shuntian Huang, Tete Daniel Koudama, Xiaodong Wu, Sheng Cui, Xiaodong Shen i Xiangbao Chen. "Tuning the Electronic Structure of a Novel 3D Architectured Co-N-C Aerogel to Enhance Oxygen Evolution Reaction Activity". Gels 9, nr 4 (7.04.2023): 313. http://dx.doi.org/10.3390/gels9040313.
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Hydrogen generation through water electrolysis is an efficient technique for hydrogen production, but the expensive price and scarcity of noble metal electrocatalysts hinder its large-scale application. Herein, cobalt-anchored nitrogen-doped graphene aerogel electrocatalysts (Co-N-C) for oxygen evolution reaction (OER) are prepared by simple chemical reduction and vacuum freeze-drying. The Co (0.5 wt%)-N (1 wt%)-C aerogel electrocatalyst has an optimal overpotential (0.383 V at 10 mA/cm2), which is significantly superior to that of a series of M-N-C aerogel electrocatalysts prepared by a similar route (M = Mn, Fe, Ni, Pt, Au, etc.) and other Co-N-C electrocatalysts that have been reported. In addition, the Co-N-C aerogel electrocatalyst has a small Tafel slope (95 mV/dec), a large electrochemical surface area (9.52 cm2), and excellent stability. Notably, the overpotential of Co-N-C aerogel electrocatalyst at a current density of 20 mA/cm2 is even superior to that of the commercial RuO2. In addition, density functional theory (DFT) confirms that the metal activity trend is Co-N-C > Fe-N-C > Ni-N-C, which is consistent with the OER activity results. The resulting Co-N-C aerogels can be considered one of the most promising electrocatalysts for energy storage and energy saving due to their simple preparation route, abundant raw materials, and superior electrocatalytic performance.
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Shafei, Layla, Puja Adhikari, Saro San i Wai-Yim Ching. "Electronic Structure and Mechanical Properties of Solvated Montmorillonite Clay Using Large-Scale DFT Method". Crystals 13, nr 7 (18.07.2023): 1120. http://dx.doi.org/10.3390/cryst13071120.
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Montmorillonite clay (MMT) has been widely used in engineering and environmental applications as a landfill barrier and toxic waste repository due to its unique property as an expandable clay mineral that can absorb water easily. This absorption process rendered MMT to be highly exothermic due to electrostatic interactions among molecules and hydrogen bonds between surface atoms. A detailed study of a large supercell model of structural clay enables us to predict long-term nuclear waste storage. Herein, a large solvent MMT model with 4071 atoms is studied using ab initio density functional theory. The DFT calculation and analysis clarify the important issues, such as bond strength, solvation effect, elasticity, and seismic wave velocities. These results are compared to our previous study on crystalline MMT (dry). The solvated MMT has reduced shear modulus (G), bulk modulus (K), and Young’s modulus (E). We observe that the conduction band (CB) in the density of states (DOS) of solvated MMT model has a single, conspicuous peak at −8.5 eV. Moreover, the atom-resolved partial density of states (PDOS) summarizes the roles played by each atom in the DOS. These findings illuminate numerous potential sophisticated applications of MMT clay.
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Xu, Maoping, Rui Wang, Kan Bian, Chuang Hou, Yaxing Wu i Guoan Tai. "Triclinic boron nanosheets high-efficient electrocatalysts for water splitting". Nanotechnology 33, nr 7 (22.11.2021): 075601. http://dx.doi.org/10.1088/1361-6528/ac368a.
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Abstract Recently, two-dimensional (2D) boron nanosheets have been predicted to exhibit exceptional physical and chemical properties, which is expected to be widely used in advanced electronics, optoelectronic, energy storage and conversion devices. However, the experimental application of 2D boron nanosheets in hydrogen evolution reactiuon (HER) has not been reported. Here, we have grown ultrathin boron nanosheets on tungsten foils via chemical vapor deposition. The prepared triclinic boron nanosheets are highly crystalline, which perfectly match the structure in the previous theoretical calculations. Notably, the boron nanosheets show excellent HER performance. The Tafel slope is only 64 mV dec−1 and the nanosheets can maintain good stability under long-time cycle in acidic solution. The improvement of performance is mainly due to the metal properties and a large number of exposed active sites on the boron nanosheets, which is confirmed by first-principle calculations.
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Spadaro, Lorenzo, Alessandra Palella i Francesco Arena. "Totally-green Fuels via CO2 Hydrogenation". Bulletin of Chemical Reaction Engineering & Catalysis 15, nr 2 (23.04.2020): 390–404. http://dx.doi.org/10.9767/bcrec.15.2.7168.390-404.
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Hydrogen is the cleanest energy vector among any fuels, nevertheless, many aspects related to its distribution and storage still raise serious questions concerning costs, infrastructure and safety. On this account, the chemical storage of renewable-hydrogen by conversion into green-fuels, such as: methanol, via CO2 hydrogenation assumes a role of primary importance, also in the light of a cost-to-benefit analysis. Therefore, this paper investigates the effects of chemical composition on the structural properties, surface reactivity and catalytic pathway of ternary CuO-ZnO-CeO2 systems, shedding light on the structure-activity relationships. Thus, a series of CuZnCeO2 catalysts, at different CuO/CeO2 ratio (i.e. 0.2-1.2) were performed in the CO2 hydrogenation reactions at 20 bar and 200-300 °C, (GHSV of 4800 STP L∙kg∙cat-1∙h-1). Catalysts were characterized by several techniques including X-ray Diffraction (XRD), N2-physisorption, single-pulse N2O titrations, X-ray Photoelectron Spectroscopy (XPS), and Temperature-programmed Reduction with H2 (H2-TPR). Depending on preparation method, the results clearly diagnostics the occurrence of synergistic structural-electronic effects of cerium oxide on copper activity, with an optimal 0.5 copper-to-cerium content. The rise of CuO loading up to 30% drives to a considerable increase of hydrogenation activity: C2Z1-C catalyst obtains the best catalytic performance, reaching methanol yield value of 12% at 300 °C. Catalyst activity proceeds according to volcano-shaped relationships, in agreement with a dual sites mechanism. Copyright © 2020 BCREC Group. All rights reserved
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Quach, Qui, Ahmed Elmekawy i Tarek M. Abdel-Fattah. "Application of Metals Modified Carbon Based Material for Hydrogen Storage". ECS Meeting Abstracts MA2022-02, nr 8 (9.10.2022): 668. http://dx.doi.org/10.1149/ma2022-028668mtgabs.
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The dependence on fossil fuel caused negative impact on the environment. It was predicted that the fossil fuel will be depleted in the near future. Various studies have been conducted to search for alternative clean energy supply. Hydrogen arises as a potential candidate due to its high energy storage and clean combustion of water vapor. However, the wide application of hydrogen energy met challenges. The hydrogen was often need to be stored in compressed tank and under specific pressures. It will require fossil fuel to provide the energy for the storage process. In order to solve that issue, different materials have been researched to store hydrogen at atmosphere pressure and room temperature. Nanomaterials materials have been used in many applications [1-30]. Carbon based materials are very attractive in many applications ranging from water purifications, catalysts support, gases purification and storage. In this study, we utilize cobalt, and nickel to improve the hydrogen storage ability of activated carbon. The activated carbon used in this study, derived from sustainable coconut shells. The structure and chemical composition of the composites was confirmed by using Powder X-Ray Diffraction (P-XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and Fourier Transform Infrared (FTIR). The BET surface area as well as the hydrogen uptake of all materials were measured using Micromeritics ASAP 2020. In conclusion, the hydrogen uptake data show that carbon-based material synthesized in this study significantly enhanced the hydrogen storage capacity. For example, the percentage of hydrogen uptake for nickel modified activated carbon was 5%. References: Biehler, Q. Quach, C. Huff, T. M. Abdel-Fattah, Materials, 15, 2692 (2022). TM Abdel-Fattah, ME Mahmoud, MM Osmam, SB Ahmed, Journal of Environmental Science and health, part A 49 (9), 1064-1076 (2014) ME Mahmoud, TM Abdel-Fattah, MM Osman, SB Ahmed, Journal of Environmental Science and Health, Part A 47 (1), 130-141 (2012) C Huff, E Biehler, Q Quach, JM Long, TM Abdel-Fattah, Colloids and Surfaces A: Physicochemical and Engineering Aspects 610 (5), 125734 (2021) K Foe, G Namkoong, TM Abdel-Fattah, H Baumgart, MS Jeong, DS Lee, Thin solid films 534, 76-82 (2013) M Abdel-Fattah, A Wixtrom, K Zhang, W Cao, H Baumgart, ECS Journal of Solid State Science and Technology 3 (10), M61 (2014) M. Abdel Fattah, M.E. Mahmoud, S.B. Ahmed, M.D. Huff, J.W. Lee, S. Kumar, Journal of Industrial and Engineering Chemistry, 22, 103-109 (2015) M. Abdel-Fattah, M.E Mahmoud, M. M. Osmam, S.B. Ahmed, Journal of Environmental Science and health part A, 49, 1064-1076 (2014) ME Mahmoud, MA Khalifa, YM El Wakeel, MS Header, TM Abdel-Fattah, Journal of Nuclear Materials 487, 13-22 (2017) C Huff, T Dushatinski, TM Abdel-Fattah, International Journal of Hydrogen Energy 42 (30), 18985-18990 (2017) SE Mohmed Labeb, Abdel-Hamed Sakr, Moataz Soliman, Tarek M.Abdel-Fattah, Optical Materials 79, 331-335 (2018) ME Mahmoud, MM Osman, SB Ahmed, TM Abdel-Fattah, Chemical engineering journal 175, 84-94 (2011) S Ebrahim, M Soliman, M Anas, M Hafez, TM Abdel-Fattah, International Journal of Photoenergy, 2013, ID 906820 (2013). TM Abdel-Fattah, ME Mahmoud, Chemical engineering journal 172 (1), 177-183 (2011) R Bhure, TM Abdel-Fattah, C Bonner, JC Hall, A Mahapatro, Journal of biomedical nanotechnology 6 (2), 117-128 (2010) TM Abdel-Fattah, D Loftis, A Mahapatro, Journal of biomedical nanotechnology 7 (6), 794-800 (201) M Stacey, C Osgood, BS Kalluri, W Cao, H Elsayed-Ali, T Abdel-Fattah, Biomedical Materials 6 (1), 011002 (2011) OH Elsayed-Ali, T Abdel-Fattah, HE Elsayed-Ali, Journal of hazardous materials 185 (2-3), 1550-1557 (2011) R Bhure, A Mahapatro, C Bonner, TM Abdel-Fattah, Materials Science and Engineering: C 33 (4), 2050-2058 (2013) BE Bishop, BA Savitzky, T Abdel-Fattah, Ecotoxicology and Environmental Safety 73 (4), 565-571 (2010) C Huff, JM Long, A Heyman, TM Abdel-Fattah, ACS Applied Energy Materials 1 (9), 4635-4640 (2018) TM Abdel-Fattah, EM Younes, G Namkoong, EM El-Maghraby, Synthetic Metals 209, 348-354 (2015) S Ebrahim, M Soliman, TM Abdel-Fattah, Journal of electronic materials 40 (9), 2033-2041 (2011) SH Lapidus, A Naik, A Wixtrom, NE Massa, V Ta Phuoc, L del Campo, Crystal growth & design 14 (1), 91-100 (2014) A Mahapatro, TD Matos Negrón, C Bonner, TM Abdel-Fattah, Journal of Biomaterials and Tissue Engineering 3 (2), 196-204 (2013) S Ebrahim, M Labeb, T Abdel-Fattah, M Soliman, Journal of Luminescence 182, 154-159 (2017)
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Zhang, Wei-De, i Wen-Hui Zhang. "Carbon Nanotubes as Active Components for Gas Sensors". Journal of Sensors 2009 (2009): 1–16. http://dx.doi.org/10.1155/2009/160698.
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The unique structure of carbon nanotubes endows them with fantastic physical and chemical characteristics. Carbon nanotubes have been widely studied due to their potential applications in many fields including conductive and high-strength composites, energy storage and energy conversion devices, sensors, field emission displays and radiation sources, hydrogen storage media, and nanometer-sized semiconductor devices, probes, and quantum wires. Some of these applications have been realized in products, while others show great potentials. The development of carbon nanotubes-based sensors has attracted intensive interest in the last several years because of their excellent sensing properties such as high selectivity and prompt response. Carbon nanotube-based gas sensors are summarized in this paper. Sensors based on single-walled, multiwalled, and well-aligned carbon nanotubes arrays are introduced. Modification of carbon nanotubes with functional groups, metals, oxides, polymers, or doping carbon nanotubes with other elements to enhance the response and selectivity of the sensors is also discussed.
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Lu, Zhuo, Changjun Jia, Xu Yang, Yongsheng Zhu, Fengxin Sun, Tianming Zhao, Shouwei Zhang i Yupeng Mao. "A Flexible TENG Based on Micro-Structure Film for Speed Skating Techniques Monitoring and Biomechanical Energy Harvesting". Nanomaterials 12, nr 9 (6.05.2022): 1576. http://dx.doi.org/10.3390/nano12091576.
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Wearable motion-monitoring systems have been widely used in recent years. However, the battery energy storage problem of traditional wearable devices limits the development of human sports training applications. In this paper, a self-powered and portable micro-structure triboelectric nanogenerator (MS-TENG) has been made. It consists of micro-structure polydimethylsiloxane (PDMS) film, fluorinated ethylene propylene (FEP) film, and lithium chloride polyacrylamide (LiCl-PAAM) hydrogel. Through the micro-structure, the voltage of the MS-TENG can be improved by 7 times. The MS-TENG provides outstanding sensing properties: maximum output voltage of 74 V, angular sensitivity of 1.016 V/degree, high signal-to-noise ratio, and excellent long-term service stability. We used it to monitor the running skills of speed skaters. It can also store the biomechanical energy which is generated in the process of speed skating through capacitors. It demonstrates capability of sensor to power electronic calculator and electronic watch. In addition, as a flexible electrode hydrogel, it can readily stretch over 1300%, which can help improve the service life and work stability of MS-TENG. Therefore, MS-TENG has great application potential in human sports training monitoring and big data analysis.
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Turkiewicz, Anna, Teresa Steliga, Dorota Kluk i Zbigniew Gminski. "Biomonitoring Studies and Preventing the Formation of Biogenic H2S in the Wierzchowice Underground Gas Storage Facility". Energies 14, nr 17 (2.09.2021): 5463. http://dx.doi.org/10.3390/en14175463.
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The article discusses the results of biomonitoring research at the Underground Gas Storage (UGS). Hydrogen sulphide, as one of the products of microbiological reaction and transformation, as well as a product of chemical reactions in rocks, is a subject of interest for global petroleum companies. The materials used in this research work were formation waters and stored natural gas. The biomonitoring of reservoir waters and cyclical analyses of the composition of gas stored at UGS Wierzchowice enabled the assessment of the microbiological condition of the reservoir environment and individual storage wells in subsequent years of operation. Investigations of the formation water from individual wells of the UGS Wierzchowice showed the presence of sulphate reducing bacteria bacteria (SRB), such as Desulfovibrio and Desulfotomaculum genera and bacteria that oxidize sulphur compounds. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide and sulphides in the reservoir waters ranged from 1.22 to 15.5 mg/dm3. The monitoring of natural gas received from UGS production wells and observation wells, which was carried out in terms of the determination of hydrogen sulphide and organic sulphur compounds, made it possible to observe changes in their content in natural gas in individual storage cycles. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide in natural gas from production wells ranged from 0.69 to 2.89 mg/dm3, and the content of organic sulphur compounds converted to elemental sulphur ranged from 0.055 to 0.130 mg Sel./Nm3. A higher hydrogen sulphide content was recorded in natural gas from observation wells in the range of 2.02–25.15 mg/Nm3. In order to explain the causes of hydrogen sulphide formation at UGS Wierzchowice, isotopic analyses were performed to determine the isotope composition of δ34SH2S, δ34SSO4, δ18OSO4 in natural gas samples (production and observation wells) and in the deep sample of reservoir water. The results of isotope tests in connection with microbiological tests, chromatographic analyses of sulphur compounds in natural gas collected from UGS Wierzchowice and an analysis of the geological structure of the Wierzchowice deposit allow us to conclude that the dominant processes responsible for the formation of hydrogen sulphide at UGS Wierzchowice are microbiological, consisting of microbial sulphate reduction (MSR). The presented tests allow for the control and maintenance of hydrogen sulphide at a low level in the natural gas received from the Wierzchowice Underground Gas Storage facility.
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Chen, Ting, Kwati Leonard, Kazunari Sasaki, Hiroshige Matsumoto i Nicola H. Perry. "Tailoring Chemical Expansion in Zirconate-Cerate Proton Conductors". ECS Meeting Abstracts MA2018-01, nr 32 (13.04.2018): 1934. http://dx.doi.org/10.1149/ma2018-01/32/1934.
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Stoichiometric chemical expansion is the lattice expansion accompanying non-integer changes in stoichiometry, such as oxygen loss in mixed ionic and electronic conducting oxides, Li intercalation in battery electrodes, H uptake in hydrogen storage materials, or hydration in proton conductors. The coefficient of chemical expansion (CCE) normalizes this chemical strain (εC) to the compositional change, so for the case of hydration in proton conductors it can be defined as CCE = εC/Δ[(OH)• O]. The chemical stresses that develop from such compositional changes can be large enough to cause mechanical failure, such as cracking or delamination, with implications for component processing, in situ characterization, and device lifetime. One way to lower the magnitude of chemical stress is to engineer materials with lower CCEs, but relatively few design principles exist to guide such engineering. In the present work we investigated the hypothesis that lower crystal symmetry could lead to lower macroscopic CCEs in polycrystalline ceramics. There are indications that such a correlation may exist among mixed ionic and electronic conducting perovskites that expand upon losing oxygen due to enlargement of multivalent cations upon gaining electrons for charge compensation. To examine whether a similar effect may be present also for the case of hydration-induced expansion, which has a different mechanism involving filling of oxygen vacancies and introduction of interstitial hydrogen, we fabricated a series of perovskite-structured proton conductors, BaY0.1Ce0.9-xZrxO3 (x=0, 0.3, 0.6, 0.9), having tailored tolerance factors – an indicator of symmetry. Bar-shaped samples were prepared by a sol-gel route and sintering to 1500 °C, and their crystal structures and lattice parameters were analyzed by X-ray diffraction with Rietveld analysis. For each composition, the isothermal expansion upon increasing H2O content in the gas atmosphere by a fixed amount was measured by dilatometry at various temperatures up to 680 °C. The corresponding changes in (OH)• O content were determined by thermogravimetric analysis under the same conditions. By normalizing the chemical strains to the changes in proton content, the CCEs at each temperature were determined for each composition and compared. X-ray diffraction confirmed that the crystal structure became more cubic and the symmetry increased with increasing x, as expected on the basis of the calculated tolerance factors. At the same time the unit cell volume increased, which could also in principle contribute to modifying the chemical expansion behavior. Proton uptake (for a given steam content) was smaller for higher x values, but the lower proton uptake did not correspond with the smallest chemical strains. In fact, the normalized CCEs monotonically increased with increasing x for all but the highest temperatures, consistent with the hypothesis of higher CCEs for higher symmetry, for these randomly oriented, polycrystalline samples. These results suggest that lowering symmetry may be a promising approach for minimizing chemical expansion behavior across multiple classes of materials, with the potential to improve material and device durability. At the same time, future studies should aim to separate the effects of unit cell size vs. crystal symmetry.
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Wongsurakul, Peerawat, Mutsee Termtanun, Worapon Kiatkittipong, Jun Wei Lim, Kunlanan Kiatkittipong, Prasert Pavasant, Izumi Kumakiri i Suttichai Assabumrungrat. "Comprehensive Review on Potential Contamination in Fuel Ethanol Production with Proposed Specific Guideline Criteria". Energies 15, nr 9 (20.04.2022): 2986. http://dx.doi.org/10.3390/en15092986.
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Ethanol is a promising biofuel that can replace fossil fuel, mitigate greenhouse gas (GHG) emissions, and represent a renewable building block for biochemical production. Ethanol can be produced from various feedstocks. First-generation ethanol is mainly produced from sugar- and starch-containing feedstocks. For second-generation ethanol, lignocellulosic biomass is used as a feedstock. Typically, ethanol production contains four major steps, including the conversion of feedstock, fermentation, ethanol recovery, and ethanol storage. Each feedstock requires different procedures for its conversion to fermentable sugar. Lignocellulosic biomass requires extra pretreatment compared to sugar and starch feedstocks to disrupt the structure and improve enzymatic hydrolysis efficiency. Many pretreatment methods are available such as physical, chemical, physicochemical, and biological methods. However, the greatest concern regarding the pretreatment process is inhibitor formation, which might retard enzymatic hydrolysis and fermentation. The main inhibitors are furan derivatives, aromatic compounds, and organic acids. Actions to minimize the effects of inhibitors, detoxification, changing fermentation strategies, and metabolic engineering can subsequently be conducted. In addition to the inhibitors from pretreatment, chemicals used during the pretreatment and fermentation of byproducts may remain in the final product if they are not removed by ethanol distillation and dehydration. Maintaining the quality of ethanol during storage is another concerning issue. Initial impurities of ethanol being stored and its nature, including hygroscopic, high oxygen and carbon dioxide solubility, influence chemical reactions during the storage period and change ethanol’s characteristics (e.g., water content, ethanol content, acidity, pH, and electrical conductivity). During ethanol storage periods, nitrogen blanketing and corrosion inhibitors can be applied to reduce the quality degradation rate, the selection of which depends on several factors, such as cost and storage duration. This review article sheds light on the techniques of control used in ethanol fuel production, and also includes specific guidelines to control ethanol quality during production and the storage period in order to preserve ethanol production from first-generation to second-generation feedstock. Finally, the understanding of impurity/inhibitor formation and controlled strategies is crucial. These need to be considered when driving higher ethanol blending mandates in the short term, utilizing ethanol as a renewable building block for chemicals, or adopting ethanol as a hydrogen carrier for the long-term future, as has been recommended.
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Smith, Thomas, Samuel Moxon, David J. Cooke, Lisa J. Gillie, Robert M. Harker, Mark T. Storr, Estelina Lora da Silva i Marco Molinari. "Structure and Properties of Cubic PuH2 and PuH3: A Density Functional Theory Study". Crystals 12, nr 10 (21.10.2022): 1499. http://dx.doi.org/10.3390/cryst12101499.
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The presence of cubic PuH2 and PuH3, the products of hydrogen corrosion of Pu, during long-term storage is of concern because of the materials’ pyrophoricity and ability to catalyse the oxidation reaction of Pu to form PuO2. Here, we modelled cubic PuH2 and PuH3 using Density Functional Theory (DFT) and assessed the performance of the PBEsol+U+SOC (0 ≤ U ≤ 7 eV) including van der Waals dispersion using the Grimme D3 method and the hybrid HSE06sol+SOC. We investigated the structural, magnetic and electronic properties of the cubic hydride phases. We considered spin–orbit coupling (SOC) and non-collinear magnetism to study ferromagnetic (FM), longitudinal and transverse antiferromagnetic (AFM) orders aligned in the <100>, <110> and <111> directions. The hybrid DFT confirmed that FM orders in the <110> and <111> directions were the most stable for cubic PuH2 and PuH3, respectively. For the standard DFT, the most stable magnetic order is dependent on the value of U used, with transitions in the magnetic order at higher U values (U > 5 eV) seen for both PuH2 and PuH3.
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Bósquez-Cáceres, María Fernanda, Lola De Lima, Vivian Morera Córdova, Anabel D. Delgado, José Béjar, Noé Arjona, Lorena Álvarez-Contreras i Juan P. Tafur. "Chitosan-Carboxymethylcellulose Hydrogels as Electrolytes for Zinc–Air Batteries: An Approach to the Transition towards Renewable Energy Storage Devices". Batteries 8, nr 12 (30.11.2022): 265. http://dx.doi.org/10.3390/batteries8120265.
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Biopolymers are promising materials as electrolytes with high flexibility, good performance, cost effectiveness, high compatibility with solvents, and film-forming ability. Chitosan (CS) and carboxymethylcellulose (CMC) can form an intermolecular complex, giving rise to hydrogels capable of absorbing ionic solutions. Citric acid (CA) is an effective biological chemical crosslinker that assists the formation of amide and ester bonds between CMC and CS, resulting in a structure with high ionic conductivity and good structural integrity. In this study, a chemical crosslinking strategy is used to synthesize electrolyte hydrogels for zinc–air batteries. The effects of crosslinking are studied on the structural and electrochemical performance of the membranes. The results show an improvement in the ionic conductivity with respect to the homologous electrolyte hydrogel systems reported, with a maximum of 0.19 S∙cm−1 at 30 °C. In addition, the cyclic voltammetry studies showed a current intensity increase at higher CA content, reaching values of 360 mA∙cm−2. Structural characterization suggests a higher thermal stability and a decrease in the degree of crystallinity caused by the polymers’ crosslinking. Finally, these membranes were tested in Zn–air batteries, obtaining power densities of 85 mW∙cm−2. The proposed hydrogels show to be appropriate for energy zinc–air battery applications and present an alternative to support the sustainable energy transition.
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Yang, Xianghua, Shiqing Wu, Qian Zhang, Songbai Qiu, Yuan Wang, Junjun Tan, Liang Ma, Tiejun Wang i Yongde Xia. "Surface Structure Engineering of PdAg Alloys with Boosted CO2 Electrochemical Reduction Performance". Nanomaterials 12, nr 21 (1.11.2022): 3860. http://dx.doi.org/10.3390/nano12213860.
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Converting carbon dioxide into high-value-added formic acid as a basic raw material for the chemical industry via an electrochemical process under ambient conditions not only alleviates greenhouse gas effects but also contributes to effective carbon cycles. Unfortunately, the most commonly used Pd-based catalysts can be easily poisoned by the in situ formed minor byproduct CO during the carbon dioxide reduction reaction (CRR) process. Herein, we report a facile method to synthesize highly uniformed PdAg alloys with tunable morphologies and electrocatalytic performance via a simple liquid synthesis approach. By tuning the molar ratio of the Ag+ and Pd2+ precursors, the morphologies, composition, and electrocatalytic activities of the obtained materials were well-regulated, which was characterized by TEM, XPS, XRD, as well as electrocatalytic measurements. The CRR results showed that the as-obtained Pd3Ag exhibited the highest performance among the five samples, with a faradic efficient (FE) of 96% for formic acid at −0.2 V (vs. reference hydrogen electrode (RHE)) and superior stability without current density decrease. The enhanced ability to adsorb and activate CO2 molecules, higher resistance to CO, and a faster electronic transfer speed resulting from the alloyed PdAg nanostructure worked together to make great contributions to the improvement of the CRR performance. These findings may provide a new feasible route toward the rational design and synthesis of alloy catalysts with high stability and selectivity for clean energy storage and conversion in the future.
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Chen, Xingyu, Xinyue Jiang i Hao Zhang. "Boosting Electro- and Photo-Catalytic Activities in Atomically Thin Nanomaterials by Heterointerface Engineering". Materials 16, nr 17 (25.08.2023): 5829. http://dx.doi.org/10.3390/ma16175829.
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Since the discovery of graphene, two-dimensional ultrathin nanomaterials with an atomic thickness (typically <5 nm) have attracted tremendous interest due to their fascinating chemical and physical properties. These ultrathin nanomaterials, referred to as atomically thin materials (ATMs), possess inherent advantages such as a high specific area, highly exposed surface-active sites, efficient atom utilization, and unique electronic structures. While substantial efforts have been devoted to advancing ATMs through structural chemistry, the potential of heterointerface engineering to enhance their properties has not yet been fully recognized. Indeed, the introduction of bi- or multi-components to construct a heterointerface has emerged as a crucial strategy to overcome the limitations in property enhancement during ATM design. In this review, we aim to summarize the design principles of heterointerfacial ATMs, present general strategies for manipulating their interfacial structure and catalytic properties, and provide an overview of their application in energy conversion and storage, including the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER), the oxygen reduction reaction (ORR), the CO2 electroreduction reaction (CO2RR), photocatalysis, and rechargeable batteries. The central theme of this review is to establish correlations among interfacial modulation, structural and electronic properties, and ATMs’ major applications. Finally, based on the current research progress, we propose future directions that remain unexplored in interfacial ATMs for enhancing their properties and introducing novel functionalities in practical applications.
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Ravalison, Francia, i Jacques Huot. "Microstructure and First Hydrogenation Properties of Ti16V60Cr24−xFex + 4 wt.% Zr Alloy for x = 0, 4, 8, 12, 16, 20, 24". Energies 16, nr 14 (14.07.2023): 5360. http://dx.doi.org/10.3390/en16145360.
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In body-centered cubic (BCC) alloys of transition elements, elemental addition or substitution in the vanadium-based alloys can be beneficial for improving the hydrogen storage properties and for reducing the production cost. In this context, the current study focused on the effect of the substitution of Cr by Fe in Ti16V60Cr24−xFex + 4 wt.% Zr alloys where x = 0, 4, 8, 12, 16, 20, 24. The microstructure of each alloy was composed of a matrix having a chemical composition close to the nominal one and a Zr-rich region. From X-ray diffraction patterns, it was found that the matrix has a BCC structure, and the Zr-rich regions present the C14 Laves phase structure. The lattice parameter of BCC phases decreased linearly with x, in accordance with Vegard’s law. The measurement of the first hydrogenation at 298 K under 3 MPa of hydrogen revealed a decrease in the maximum hydrogen capacity: 3.8 wt.% for x = 0, 3.1 wt.% for x = 4 and around 2 wt.% for x = 8 to 24. The XRD patterns after hydrogenation showed a BCT phase for all alloys, with a C14 phase for x = 4, 8, 12 and with C14 and C15 for x = 16, 20 and 24.
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Zhou, Li, Huadong Zhu i Wen Zeng. "Density Functional Theory Study on the Adsorption Mechanism of Sulphide Gas Molecules on α-Fe2O3(001) Surface". Inorganics 9, nr 11 (4.11.2021): 80. http://dx.doi.org/10.3390/inorganics9110080.
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Sulphide gas is an impurity that affects the quality of natural gas, which needs reasonable storage and transportation. In this work, we investigated the adsorption structure and electronic behavior of hydrogen sulfide (H2S), carbonyl sulfur (COS), and methyl mercaptan (CH3SH) on sulphide gas molecules on pure and vacant α-Fe2O3(001) surfaces by density functional theory with geometrical relaxations. The results show that H2S and CH3SH are mainly adsorbed in the form of molecules on the pure Fe2O3(001) surface. On the vacant α-Fe2O3(001) surface, they can be adsorbed on Fe atoms in molecular form and by dissociation. The absolute value of the adsorption energy of H2S and CH3SH on the vacancy defect α-Fe2O3 surface is larger, and the density of states show that the electron orbital hybridization is more significant, and the adsorption is stronger. The charge differential density and Mulliken charge population analysis show that the charge is rearranged and chemical bonds are formed. The affinity of H2S to the vacancy α-Fe2O3(001) surface is slightly higher than that of CH3SH, while COS molecules basically do not adsorb on the α-Fe2O3(001) surface, which may be related to the stable chemical properties of the molecules themselves.
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Soldatov, Mikhail, Kirill Lomachenko, Nikolay Smolentsev i Alexander Soldatov. "Determination of the local structure in metal-complexes by combining XAS and XES". Acta Crystallographica Section A Foundations and Advances 70, a1 (5.08.2014): C1521. http://dx.doi.org/10.1107/s2053273314084782.
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Nanoscale local atomic structure determines most of unique properties of novel materials without long range order. To study its fine details one has to use both computer nanodesign and advanced experimental methods for nanodiagnostics. The status of modern theoretical analysis of the experimental x-ray absorption spectra to extract structural parameters is presented. Novel in-situ technique for nanodiagnostics - extracting of 3D structure parameters on the basis of advanced quantitative analysis of X-ray absorption near edge structure (XANES) - has been developed. The possibility to extract information on bond angles and bond-lengths (with accuracy up to 0.002 nm) is demonstrated and it opens new perspectives of quantitative XANES analysis as a 3D local structure probe for any type of materials without long range order in atoms positions (all nanostructured materials and free clusters belong to this class of materials). Even more possibilities are opening by using simultaneously several experimental synchrotron based techniques: XANES and XES and/or RIXS. In the framework of these approaches, the results of recent studies of local atomic structure for several types of nanostructures including nanoclusters with different types of chemical bonding, core-shell nanoneedles and thin films of dilute magnetic semiconductors, 5d-transition metal-organic complexes, Cu1+ and Cu2+ binding sites in amyloid-β peptide, Co aqua complexes in aqueous solution, nanostructured materials for hydrogen storage and nanocatalysts based on zeolites and MOF are reported. Along with the calculations of conventional XANES and XES, we show a possibility to simulate core-to-core and valence-to-core RIXS as well. Molecular orbitals (or DOS) of metal complexes can be directly related to the peaks in XES spectra in RIXS maps. This information is essential for understanding of electronic structure of metal complexes and design of novel materials.
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Lv, Xuefeng, Guangsheng Liu, Song Liu, Wenting Chen, Dehua Cao, Taize Song, Nannan Wang i Yanqiu Zhu. "Three-Dimensional Flower-like Fe, C-Doped-MoS2/Ni3S2 Heterostructures Spheres for Accelerating Electrocatalytic Oxygen and Hydrogen Evolution". Crystals 11, nr 4 (28.03.2021): 340. http://dx.doi.org/10.3390/cryst11040340.
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The exploration of high-efficiency bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has long been challenging. The rational design of a catalyst by constructing heterostructures and a doping element are possibly expected to achieve it. Herein, the utilization of flower-like Fe/C-doped-MoS2/Ni3S2-450 spherical structural materials for electrocatalytic HER and OER is introduced in this study. The carboxyferrocene-incorporated molybdenum sulfide/nickel sulfide (MoySx/NiS) nanostructures were prepared by solvothermal method. After annealing, the iron and carbon elements derived from ferrocenecarboxylic acid enhanced the electrical transport performance and provided rich electronic sites for HER and OER in alkaline media. Specifically, the optimized flower-like Fe/C-doped-MoS2/Ni3S2-450 exhibited efficient bifunctional performance in alkaline electrolyte, with low overpotentials of 188 and 270 mV required to deliver a current density of 10 mA cm−2 for HER and OER, respectively. This work provides valuable insights for the rational design of energy storage and conversion materials by the incorporation of transition metal and carbon elements into metal sulfide structures utilizing metallocene.
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Grant, Daniel J., i David A. Dixon. "Thermodynamic Properties of Molecular Borane Phosphines, Alane Amines, and Phosphine Alanes and the [BH4-][PH4+], [AlH4-][NH4+], and [AlH4-][PH4+] Salts for Chemical Hydrogen Storage Systems from ab Initio Electronic Structure Theory". Journal of Physical Chemistry A 109, nr 44 (listopad 2005): 10138–47. http://dx.doi.org/10.1021/jp054152y.
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Jin, Xinfang, Puvikkarasan Jayapragasam, Yeting Wen i Kevin Huang. "Electro-Chemical-Mechanical Coupled Modeling of Oxygen Electrodes in Solid Oxide Electrolyzer Cells". ECS Meeting Abstracts MA2022-01, nr 37 (7.07.2022): 1621. http://dx.doi.org/10.1149/ma2022-01371621mtgabs.
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Solid oxide electrolyzer cell (SOECs), which is an electrochemical device to split water with electricity to generate hydrogen, have received widespread attention for multi-day or seasonal energy storage to integrate variable renewable energy (VRE) into the grid [1]. Even though there have been tremendous material development and performance improvement of the technology in the past decade [2], challenges remain in understanding its degradation mechanism, especially the delamination of oxygen electrode/electrolyte interface [3-5]. Developing new oxygen electrodes which could decelerate the degradation and extend the stack lifetime beyond 60,000 hours at 1.5A/cm2 would significantly drive the stack price down to $100/kW and hydrogen cost down to $2/kg [6]. In the state-of-the-art SOECs, pure ionic conductor 8 mol% Y2O3 doped ZrO2 (YSZ) and Gadolinium-doped Ceria (GDC) are usually used as the dense electrolyte and the buffer layer; mixed electronic and ionic conductor (MIEC) La1-xSrxCo1-yFeyO3-d (LSCF) is widely used as the oxygen electrode [7]. Such cells still suffer from short lifetimes with current densities over 1A/cm2. To overcome the challenge, a bilayer oxygen electrode structure, consisting of a commercial LSCF-GDC porous backbone coated by a thin SrCo0.9Ta0.1O3- d (SCT10) film (denoted as LSCF-SCT bilayer design), has been proposed and demonstrated with much higher performance compared to traditional LSCF electrode (single layer design) [8]. The new oxygen electrode has an inherently fast oxygen evolution reaction (OER) electrokinetics (or high oxygen evolution rate) and can mitigate the delamination problem by minimizing the accumulation of oxygen in oxygen evoluation reaction (OER) electrode lattice and thus chemical stresses. In this study, based upon an Electro-Chemical-Mechanical coupled model, we will correlate the crack length at the oxygen electrode/electrolyte interface with the electrochemical performance of the cell, specifically the voltage-current curve (Fig.1a). We will use J-integral (Fig.1b) as the fracture criteria to evaluate the crack growth rate under different current densities and with different oxygen electrode designs. LSCF single layer design is the baseline of the study. The long-term performance improvement of LSCF-SCT bilayer design will be compared against the baseline and its degradation mechanism will be investigated. The model will also be validated by long-term overpotential testing data as a function of time under 1A/cm2. It will be used as an optimization tool to mitigate delamination and extend the cell lifetime under higher current densities. Key Words: Electrolysis, Oxygen Electrode (OE), Delamination, Chemical Expansion, J integral, Crack Growth Rate Figure 1
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Adhikari, Chandan, i Rehana Farooq. "Recent Developments in the Synthesis and Applications of Metal Organic Framework: A Concise Review". Asian Journal of Chemistry 33, nr 5 (2021): 956–62. http://dx.doi.org/10.14233/10.14233/ajchem.2021.23055.
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Metal organic frameworks (MOFs) are one of those compounds which have drawn attention in various applications due to their several interesting properties like tunable shape, size, pore size, easy functionalization, high surface area, pore volume, etc. Metal organic frameworks due to their uniform structures, tunable porosity, wide variety and stability on various topology, geometry, dimension and chemical functions of the molecular network give a remarkable structural diversity in comparison to other porous materials. This enables scientists to handle numerous framework structures, porosity and functionality effectively. The unique structural architecture and tunable properties of MOF’s makes them an interesting hybrid material consisting of organic and inorganic materials. MOF can be randomly constructed like Lego bricks and superior in terms of versatility in comparisson to other porous materials. A number of MOFs containing a wide variety of metal e.g. zinc, copper, iron, aluminium, magnesium, chromium, zirconium, gadolinium, manganese are gaining rapid growth in commercial markets for gas storage, adsorption, separation and catalytic applications. This concise review emphasizes various synthetic methods e.g. solvothermal process, hydrothermal synthesis, electrochemical synthesis, microwave synthesis, sonochemical synthesis, mechanochemical synthesis, of metal organic framework developed in the last few decades. It also addresses various applications of metal organic framework e.g. hydrogen storage, gas adsorption, drug delivery systems and bioimaging agents, biocatalysts, biosensors, electrochemical sensors, etc. It also comments on various challenges and futuristic applications of metal organic frameworks in various field e.g. liquid wate management, gaseous waste management, sunlight assisted catalysis, water purification, building materials, electronic devices, battery technologies, targeted drug delivery, solar cells, etc. of science and technology in coming decades.
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He, Chubin, Xiuru Xu, Yang Lin, Yang Cui i Zhengchun Peng. "A Bilayer Skin-Inspired Hydrogel with Strong Bonding Interface". Nanomaterials 12, nr 7 (29.03.2022): 1137. http://dx.doi.org/10.3390/nano12071137.
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Conductive hydrogels are widely used in sports monitoring, healthcare, energy storage, and other fields, due to their excellent physical and chemical properties. However, synthesizing a hydrogel with synergistically good mechanical and electrical properties is still challenging. Current fabrication strategies are mainly focused on the polymerization of hydrogels with a single component, with less emphasis on combining and matching different conductive hydrogels. Inspired by the gradient modulus structures of the human skin, we propose a bilayer structure of conductive hydrogels, composed of a spray-coated poly(3,4-dihydrothieno-1,4-dioxin): poly(styrene sulfonate) (PEDOT:PSS) as the bonding interface, a relatively low modulus hydrogel on the top, and a relatively high modulus hydrogel on the bottom. The spray-coated PEDOT:PSS constructs an interlocking interface between the top and bottom hydrogels. Compared to the single layer counterparts, both the mechanical and electrical properties were significantly improved. The as-prepared hydrogel showed outstanding stretchability (1763.85 ± 161.66%), quite high toughness (9.27 ± 0.49 MJ/m3), good tensile strength (0.92 ± 0.08 MPa), and decent elastic modulus (69.16 ± 8.02 kPa). A stretchable strain sensor based on the proposed hydrogel shows good conductivity (1.76 S/m), high sensitivity (a maximum gauge factor of 18.14), and a wide response range (0–1869%). Benefitting from the modulus matching between the two layers of the hydrogels, the interfacial interlocking network, and the patch effect of the PEDOT:PSS, the strain sensor exhibits excellent interface robustness with stable performance (>12,500 cycles). These results indicate that the proposed bilayer conductive hydrogel is a promising material for stretchable electronics, soft robots, and next-generation wearables.
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Upadhyay, Sanjay, i O. P. Pandey. "Review—Synthesis and Electrochemical Applications of Molybdenum Carbide: Recent Progress and Perspectives". Journal of The Electrochemical Society 169, nr 1 (1.01.2022): 016511. http://dx.doi.org/10.1149/1945-7111/ac4a52.
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In this review, we summarize the latest research progress on Mo2C based materials for various electrochemical applications. It starts with discussing the different synthesis methods and the tactics for modifying the physicochemical characteristics of Mo2C. In addition, the variables that influence the morphology and electrochemical performance of Mo2C have been explored. The synthesis methods are examined based on their tricks, benefits, and drawbacks, including solid-gas, solid-solid, solid-liquid, and some other processes (chemical vapor deposition, Sonochemical, microwave-assisted, plasma, etc.). Methods that are safe, cost-effective, environmentally friendly, and suited for large-scale production of Mo2C are given special consideration. The solid-solid reaction is found to be a facile and cost-effective method to synthesize Mo2C structures having high surface area and small particle size. Also, the various electrochemical applications of Mo2C are reviewed. Mo2C is an extremely active and durable electrocatalyst mainly for hydrogen evolution reaction (HER). The electrochemical parameters such as activity, stability, etc., are examined and described in detail. The possible ways to improve the electrochemical performance of Mo2C are discussed. Finally, the difficulties in developing Mo2C nanostructures that are suited for energy storage and conversion applications are discussed.
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Gupta, M. "Electronic structure of hydrogen storage materials". International Journal of Quantum Chemistry 77, nr 6 (2000): 982–90. http://dx.doi.org/10.1002/(sici)1097-461x(2000)77:6<982::aid-qua6>3.0.co;2-#.
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Gupta, Michèle. "Electronic Structure of Intermetallic Hydrides for Hydrogen Storage". Materials Science Forum 31 (styczeń 1988): 77–110. http://dx.doi.org/10.4028/www.scientific.net/msf.31.77.
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Wu, Chengzhang, Guotao Wu, Zhitao Xiong, Xiuwen Han, Hailiang Chu, Teng He i Ping Chen. "LiNH2BH3·NH3BH3: Structure and Hydrogen Storage Properties". Chemistry of Materials 22, nr 1 (12.01.2010): 3–5. http://dx.doi.org/10.1021/cm903167b.
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Smardz, L., M. Jurczyk, K. Smardz, M. Nowak, M. Makowiecka i I. Okonska. "Electronic structure of nanocrystalline and polycrystalline hydrogen storage materials". Renewable Energy 33, nr 2 (luty 2008): 201–10. http://dx.doi.org/10.1016/j.renene.2007.05.006.
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Van de Walle, Chris G., A. Peles, A. Janotti i G. B. Wilson-Short. "Atomic and electronic structure of hydrogen-related centers in hydrogen storage materials". Physica B: Condensed Matter 404, nr 5-7 (kwiecień 2009): 793–97. http://dx.doi.org/10.1016/j.physb.2008.11.171.
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Kelton, K. F., i P. C. Gibbons. "Hydrogen Storage in Quasicrystals". MRS Bulletin 22, nr 11 (listopad 1997): 69–72. http://dx.doi.org/10.1557/s0883769400034473.
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Quasicrystals may have important applications as new technological materials. In particular, work in our laboratory has shown that some quasicrystals may be useful as hydrogen-storage materials.Some transition metals have a capacity to store hydrogen to a density exceeding that of liquid hydrogen. Such systems allow for basic investigations of solid-state phenomena such as phase transitions, atomic diffusion, and electronic structure. They may also be critical materials for the future energy economy. The depletion of the world's petroleum reserves and the increased environmental impact of conventional combustion-engine powered automobiles are leading to renewed interest in hydrogen. TiFe hydrides have already been used as storage tanks for stationary nonpolluting hydrogen internal-combustion engines. Nickel metal-hydride batteries are commonly used in a wide range of applications, most notably as power sources for portable electronic devices—particularly computers. The light weight and low cost of titanium-transition-metal alloys offer significant advantages for such applications. Unfortunately they tend to form stable hydrides, which prevents the ready desorption of the stored hydrogen for the intended use.Some titanium/zirconium quasicrystals have a larger capacity for reversible hydrogen storage than do competing crystalline materials. Hydrogen can be loaded from the gas phase at temperatures as low as room temperature and from an electrolytic solution. The hydrogen goes into solution in the quasicrystal structure, often avoiding completely the formation of undesirable crystalline hydride phases. The proven ability to reversibly store variable quantities of hydrogen in a quasicrystal not only points to important areas of application but also opens the door to previously inaccessible information about the structure and dynamics of this novel phase. Selected results illustrating these points appear briefly here.
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Yang, Xinchun, Dmitri A. Bulushev, Jun Yang i Quan Zhang. "New Liquid Chemical Hydrogen Storage Technology". Energies 15, nr 17 (31.08.2022): 6360. http://dx.doi.org/10.3390/en15176360.
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The liquid chemical hydrogen storage technology has great potentials for high-density hydrogen storage and transportation at ambient temperature and pressure. However, its commercial applications highly rely on the high-performance heterogeneous dehydrogenation catalysts, owing to the dehydrogenation difficulty of chemical hydrogen storage materials. In recent years, the chemists and materials scientists found that the supported metal nanoparticles (MNPs) can exhibit high catalytic activity, selectivity, and stability for the dehydrogenation of chemical hydrogen storage materials, which will clear the way for the commercial application of liquid chemical hydrogen storage technology. This review has summarized the recent important research progress in the MNP-catalyzed liquid chemical hydrogen storage technology, including formic acid dehydrogenation, hydrazine hydrate dehydrogenation and ammonia borane dehydrogenation, discussed the urgent challenges in the key field, and pointed out the future research trends.
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Mounkachi, Omar, Asmae Akrouchi, Ghassane Tiouitchi, Marwan Lakhal, Elmehdi Salmani, Abdelilah Benyoussef, Abdelkader Kara, Abdellah El Kenz, Hamid Ez-Zahraouy i Amine El Moutaouakil. "Stability, Electronic Structure and Thermodynamic Properties of Nanostructured MgH2 Thin Films". Energies 14, nr 22 (18.11.2021): 7737. http://dx.doi.org/10.3390/en14227737.
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Magnesium is an attractive hydrogen storage candidate due to its high gravimetric and volumetric storage capacities (7.6 wt.% and 110 gH2/l, respectively). Unfortunately, its use as a storage material for hydrogen is hampered by the high stability of its hydride, its high dissociation temperature of 573–673 K and its slow reaction kinetics. In order to overcome those drawbacks, an important advancement toward controlling the enthalpy and desorption temperatures of nano-structured MgH2 thin films via stress/strain and size effects is presented in this paper, as the effect of the nano-structuring of the bulk added to a biaxial strain on the hydrogen storage properties has not been previously investigated. Our results show that the formation heat and decomposition temperature correlate with the thin film’s thickness and strain/stress effects. The instability created by decreasing the thickness of MgH2 thin films combined with the stress/strain effects induce a significant enhancement in the hydrogen storage properties of MgH2.
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Qin, Wei, Lu Han, Hai Bi, Jiahuang Jian, Xiaohong Wu i Peng Gao. "Hydrogen storage in a chemical bond stabilized Co9S8–graphene layered structure". Nanoscale 7, nr 47 (2015): 20180–87. http://dx.doi.org/10.1039/c5nr06116d.
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With the high energy ball milling method, a Co9S8-decorated reduced graphene oxide (RGO) composite, which shows excellent hydrogen storage capacity, has been successfully fabricated with a well-organized layered structure.
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Duffin, Andrew M., Alice H. England, Craig P. Schwartz, Janel S. Uejio, Gregory C. Dallinger, Orion Shih, David Prendergast i Richard J. Saykally. "Electronic structure of aqueous borohydride: a potential hydrogen storage medium". Physical Chemistry Chemical Physics 13, nr 38 (2011): 17077. http://dx.doi.org/10.1039/c1cp21788g.
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Chua, Yong Shen, Guotao Wu, Zhitao Xiong, Teng He i Ping Chen. "Calcium Amidoborane Ammoniate—Synthesis, Structure, and Hydrogen Storage Properties". Chemistry of Materials 21, nr 20 (27.10.2009): 4899–904. http://dx.doi.org/10.1021/cm9020222.
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Novák, Pavel, Dalibor Vojtěch, Filip Průša, Jan Šerák i Thomáš Fabián. "Structure and Properties of Magnesium-Based Hydrogen Storage Alloys". Materials Science Forum 567-568 (grudzień 2007): 217–20. http://dx.doi.org/10.4028/www.scientific.net/msf.567-568.217.
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Hydrogen is the promising pollutant-free fuel of the near future. For various hydrogen applications, suitable storage systems have to be developed. One of the safe ways is the reversible storage of hydrogen in the form of light metal (lithium or magnesium) hydrides. MgH2 magnesium hydride shows very high storage capacity (approx. 7 wt. %), but its problem is high thermodynamic stability. Therefore, high temperature (over 400°C) is necessary for MgH2 to decompose producing hydrogen. The solution of this problem can be the utilization of the complex magnesium hydrides containing nickel, copper or other transition metals. In this work, the microstructure and hydrogen storage properties of the various magnesium alloys (Mg-Ni, Mg-Zn, Mg-Cu and Mg-Cu-Al) are described. The aim was to find suitable hydrogen storage system with good storage capacity and sufficient rate of formation and decomposition of hydrides. Microstructure, chemical and phase composition of the alloys were determined by the light and scanning electron microscopy, EDS and XRD. Hydrogen saturation was carried out by cathodic polarization in the alkaline solution. Hydrogen content in the material was estimated by XRD from the shift of the diffraction lines of present phases.