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Artículos de revistas sobre el tema "Desorption energy"

Autor: Grafiati

Publicado: 10 de marzo de 2023

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1

Zhang, Binbin, Jiacheng Peng, Ye Li, Huancong Shi, Jing Jin, Jiawei Hu y Shijian Lu. "Evaluating CO2 Desorption Activity of Tri-Solvent MEA + EAE + AMP with Various Commercial Solid Acid Catalysts". Catalysts 12, n.º 7 (30 de junio de 2022): 723. http://dx.doi.org/10.3390/catal12070723.

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The Paris Agreement and one of its goals, “carbon neutrality,” require intensive studies on CO2 absorption and desorption processes. When searching for ways of reducing the huge energy cost of CO2 desorption in the amine scrubbing process, the combination of blended amine with solid acid catalysts turned out to be a powerful solution in need of further investigation. In this study, the tri-solvent MEA (monoethanolamine) + EAE(2-(ethylamino)ethanol) + AMP(2-amino-2-methyl-1-propanol) was prepared at: 0.2 + 2 + 2, 0.5 + 2 + 2, 0.3 + 1.5 + 2.5 and 0.2 + 1 + 3 mol/L. The heterogeneous catalytic CO2 desorptions were tested with five commercial catalysts: blended γ-Al2O3/H-ZSM-5, H-beta, H-mordenite, HND-8 and HND-580. Desorption experiments were conducted via a recirculation process with direct heating at 363 K or using temperature programming method having a range of 303–363 K. Then, the average CO2 desorption rate, heat duty and desorption factors were studied. After comparison, the order of CO2 desorption performance was found to be HND-8 > HND-580 > H-mordenite > Hβ > blended γ-Al2O3/H-ZSM-5 > no catalyst. Among the other combinations, the 0.2 + 1 + 3 mol/L MEA + EAE + AMP with HND-8 had a minimized heat duty (HD) of 589.3 kJ/mol CO2 and the biggest desorption factor (DF) of 0.0277 * (10−3 mol CO2)3/L2 kJ min. This study provided a kind of tri-solvent with catalysts as an energy-efficient solution for CO2 absorption and desorption in industrial CO2 capture pilot plants.

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2

van der Ham, L. V., P. Khakharia y E. L. V. Goetheer. "Heat-Integrated Liquid–Desorption Exchanger (HILDE) for CO2 Desorption". Energy Procedia 86 (enero de 2016): 106–15. http://dx.doi.org/10.1016/j.egypro.2016.01.011.

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3

Wei, Fu Gao, Kaneaki Tsuzaki y Toru Hara. "A New Method to Determine the Activation Energy for Hydrogen Desorption from Steels". Materials Science Forum 475-479 (enero de 2005): 229–32. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.229.

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A new method has been developed to determine the activation energy for hydrogen desorption from steels by means of thermal desorption spectrometry (TDS). This method directly fits the Kissinger’s reaction kinetic formula dX/dt=A(1-X)exp(-Ed/RT) to experimentally measured thermal desorption spectrum and best fit yields the activation energy (Ed) and the value of constant A. It has been proven that this new method is applicable to precise measurement of the activation energy for hydrogen desorption from incoherent TiC particle, coherent TiC precipitate, grain boundary and dislocation in 0.05C-0.20Ti-2.0Ni and 0.42C-0.30Ti steels.

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4

Kuznetsov Yu. A. y Lapushkin M.N. "Energy Characteristics of Electron-Stimulated Desorption of Lithium Atoms from Lithium Layers on the Li-=SUB=-x-=/SUB=-Au-=SUB=-y-=/SUB=- Surface". Physics of the Solid State 64, n.º 6 (2022): 733. http://dx.doi.org/10.21883/pss.2022.06.53840.287.

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The formation of 2D LixAuy semiconductor layers on the surface of gold deposited on a tungsten substrate has been studied. The processes of electron-stimulated desorption of Li atoms in the Li/LixAuy/Au/W system are considered. The presence of two peaks in the kinetic energy distribution of desorbed lithium atoms is shown: a high energy peak at an energy of 0.3 eV and a low energy peak at an energy of 0.11 eV. The high energy peak is associated with the desorption of lithium atoms from the adsorbed lithium layers, and the low energy peak is associated with the LixAuy intermetallic compound. The influence of the number of deposited gold and lithium atoms on the process of formation of 2D semiconductor LixAuy layers is studied. It is shown that the processes of electron-stimulated desorption occur in the Li monolayer and the LixAuy layer closest to it. A model of electron-stimulated desorption of Li atoms in the Li/LixAuy/Au/W system is proposed. Keywords: electron-stimulated desorption, lithium, gold, semiconductor, intermetallic compound.

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5

Furuya, Kenji, Yasuhiro Oba y Takashi Shimonishi. "Quantifying the Chemical Desorption of H₂S and PH₃ from Amorphous Water-ice Surfaces". Astrophysical Journal 926, n.º 2 (1 de febrero de 2022): 171. http://dx.doi.org/10.3847/1538-4357/ac4260.

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Abstract Nonthermal desorption of molecules from icy grain surfaces is required to explain molecular line observations in the cold gas of star-forming regions. Chemical desorption is one of the nonthermal desorption processes and is driven by the energy released by chemical reactions. After an exothermic surface reaction, the excess energy is transferred to products’ translational energy in the direction perpendicular to the surface, leading to desorption. The desorption probability of product species, especially that of product species from water-ice surfaces, is not well understood. This uncertainty limits our understanding of the interplay between gas-phase and ice-surface chemistry. In the present work, we constrain the desorption probability of H2S and PH3 per reaction event on porous amorphous solid water (ASW) by numerically simulating previous laboratory experiments. Adopting the microscopic kinetic Monte Carlo method, we find that the desorption probabilities of H2S and PH3 from porous ASW per hydrogen-addition event of the precursor species are 3% ± 1.5% and 4% ± 2%, respectively. These probabilities are consistent with a theoretical model of chemical desorption proposed in the literature if ∼7% of energy released by the reactions is transferred to the translational excitation of the products. As a byproduct, we find that approximately 70% (40%) of adsorption sites for atomic H on porous ASW should have a binding energy lower than ∼300 K (∼200 K). The astrochemical implications of our findings are briefly discussed.

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6

He, Jiao y Gianfranco Vidali. "Application of a diffusion–desorption rate equation model in astrochemistry". Faraday Discuss. 168 (2014): 517–32. http://dx.doi.org/10.1039/c3fd00113j.

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Desorption and diffusion are two of the most important processes on interstellar grain surfaces; knowledge of them is critical for the understanding of chemical reaction networks in the interstellar medium (ISM). However, a lack of information on desorption and diffusion is preventing further progress in astrochemistry. To obtain desorption energy distributions of molecules from the surfaces of ISM-related materials, one usually carries out adsorption–desorption temperature programmed desorption (TPD) experiments, and uses rate equation models to extract desorption energy distributions. However, the often-used rate equation models fail to adequately take into account diffusion processes and thus are only valid in situations where adsorption is strongly localized. As adsorption–desorption experiments show that adsorbate molecules tend to occupy deep adsorption sites before occupying shallow ones, a diffusion process must be involved. Thus, it is necessary to include a diffusion term in the model that takes into account the morphology of the surface as obtained from analyses of TPD experiments. We take the experimental data of CO desorption from the MgO(100) surface and of D₂ desorption from amorphous solid water ice as examples to show how a diffusion–desorption rate equation model explains the redistribution of adsorbate molecules among different adsorption sites. We extract distributions of desorption energies and diffusion energy barriers from TPD profiles. These examples are contrasted with a system where adsorption is strongly localized – HD from an amorphous silicate surface. Suggestions for experimental investigations are provided.

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7

Yang, Qian Ming y Yong Guo Luo. "Performance Analysis of CO₂ Capture System by MEA Method Based on Solar Assisted Heat Pump Technology". Advanced Materials Research 236-238 (mayo de 2011): 518–22. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.518.

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The MEA method basic process and CO2 capture system by the MEA method based on the lean solution source heat pump technology have been introduced. The desorption energy consumption of the system has been analyzed and caculated. The results show that heat pump technology combined with MEA method can reduce desorption energy consumption of system substantially. A new type of CO2 capture system by the MEA method with the solar-lean solution compound source heat pump providing desorption heat is put forward，whose thermodynamic performance is analyzed and the result indicates that desorption energy consumption can be decreased further by applying the solar assisted heat pump technology in the MEA method.

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8

Elkhatib, E. A., A. M. Mahdy y N. H. Barakat. "Thermodynamics of copper desorption from soils as affected by citrate and succinate". Soil and Water Research 2, No. 4 (7 de enero de 2008): 135–40. http://dx.doi.org/10.17221/2110-swr.

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Desorption of Cu and low molecular weight dissolved organics are the primary factors that impact fate and transport of Cu in soils. To improve predictions of the toxicity and threat from Cu contaminated soil, it is critical that time-dependent desorption behaviour be understood. In this paper, the effect of organic ligands citrate and succinate on the kinetics of Cu desorption from contaminated soils varying widely in soil characteristics was investigated at three different temperatures. The results showed that the first order equation adequately described the kinetics of Cu desorption from clay and sandy soils under isothermal conditions. The reaction rate constant (k<sub>d</sub>) values of the first order kinetic equation for Cu desorption increased consistently with temperature, indicating faster release of Cu at higher temperatures. The Cu desorption rate from the studied soils at all three temperatures was as follows: citric > succinic. The E<sub>a</sub>values indicates that Cu desorption from the studied soils in the presence of two organic ligands is a diffusion controlled reaction. The negative values of ΔH* suggest that the desorption reactions are not energy consuming process. The higher negative values of (ΔH*) for Cu desorption from the studied soils in the presence of succinic ligand indicate that the heat energy required to overcome the Cu desorption barrier was greater than that for Cu desorption in the presence of citric ligand. Computation of the free energy of activation (ΔG*) yielded values ranging for 87 to 87.9 kJ/mol. The largest value represents ΔG* for Cu desorption for clay soil in the presence of succinic acid while the lowest value represents ΔG* for Cu desorption for sandy soil in the presence of citric acid. The information in this study is quite necessary to construct full functioning models that will help scientists to better understand mobility and bioavailability of metals in soils.

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9

Кузнецов, Ю. А. y М. Н. Лапушкин. "Энергетические характеристики электронно-стимулированной десорбции атомов лития из слоев лития на поверхности Li-=SUB=-x-=/SUB=-Au-=SUB=-y-=/SUB=-". Физика твердого тела 64, n.º 6 (2022): 732. http://dx.doi.org/10.21883/ftt.2022.06.52401.287.

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The formation of 2D LixAuy semiconductor layers on the surface of gold deposited on a tungsten substrate has been studied. The processes of electron-stimulated desorption of Li atoms in the Li/LixAuy/Au/W system are considered. The presence of two peaks in the kinetic energy distribution of desorbed lithium atoms is shown: a high energy peak at an energy of 0.3 eV and a low energy peak at an energy of 0.11 eV. The high energy peak is associated with the desorption of lithium atoms from the adsorbed lithium layers, and the low energy peak is associated with the LixAuy intermetallic compound. The influence of the number of deposited gold and lithium atoms on the process of formation of 2D semiconductor LixAuy layers is studied. It is shown that the processes of electron-stimulated desorption occur in the Li monolayer and the LixAuy layer closest to it. A model of electron-stimulated desorption of Li atoms in the Li/LixAuy/Au/W system is proposed.

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10

Chen, Xuexi, Liang Zhang y Maoliang Shen. "Experimental research on desorption characteristics of gas-bearing coal subjected to mechanical vibration". Energy Exploration & Exploitation 38, n.º 5 (31 de agosto de 2020): 1454–66. http://dx.doi.org/10.1177/0144598720956286.

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Mechanical vibration can induce coal and gas outburst accidents, and can also promote the exploitation of coalbed methane. In this paper, a vibration-adsorption-desorption experiment system was established, the effects of coal sample particle diameter, gas pressure, and vibration frequency on gas desorption were studied. Mechanical vibration can generate a shear force in the adsorbed gas and promote gas desorption, but there are appropriate vibration parameters. Within the range of experimental parameters, the larger the amplitude, the more favorable for gas desorption. The change rules of gas desorption rate and desorption quantity under different conditions are basically the same, showing a power function shape with time increase, and most of the desorption quantity was completed within the first 5 minutes. The gas desorption rate and desorption quantity were positively related to the gas adsorption pressure. The results have great reference value for preventing gas outbursts and promoting gas exploitation.

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11

Tachibana, Takayuki, Luca Chiari, Masaru Nagira, Takato Hirayama y Yasuyuki Nagashima. "Ion Desorption from TiO₂(110) by Low Energy Positron Impact". Defect and Diffusion Forum 373 (marzo de 2017): 324–27. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.324.

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We have observed positron-stimulated ion desorption from a TiO2(110) surface. H+ and O+ ions were desorbed at incident positron energies above the desorption thresholds for electron impact. However, only O+ ions were detected at energies below those thresholds. These results suggest that by surface ionization positron annihilation as well as by positron impact leads to the O+ ion desorption. By contrast, it is likely that the H+ ions are not desorbed by positron annihilation, but rather by impact ionization.

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12

Li, Zhong, Hongjuan Wang, Hongxia Xi, Qibin Xia, Jinglei Han y Lingai Luo. "Estimation of Activation Energy of Desorption of n-Hexanol from Activated Carbons by the TPD Technique". Adsorption Science & Technology 21, n.º 2 (marzo de 2003): 125–33. http://dx.doi.org/10.1260/026361703769013862.

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Activated carbon and five kinds of metal-ion-substituted activated carbons, viz. Ag+-activated carbon, Cu2+-activated carbon, Fe3+-activated carbon, Ba2+-activated carbon and Ca2+-activated carbon, were prepared. A model for estimating the activation energy of desorption was established. Temperature-programmed desorption (TPD) experiments were conducted to measure the TPD curves of n-hexanol and hence estimate the activation energy for n-hexanol desorption from the various activated carbons. The results showed that the activation energies for n-hexanol desorption from the Ag+-activated carbon, the Cu2+-activated carbon and the Fe3+-activated carbon were higher than those from the unsubstituted activated carbon, the Ca2+-activated carbon and the Ba2+-activated carbon.

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13

Li, Hou-Jun, Liang Cheng, Peng Sun, Fang-Fang Li y Jun Qiu. "Potential Analysis of Atmospheric Water Harvesting Technologies from the Perspective of “Trading-in Energy for Water”". Water 15, n.º 5 (24 de febrero de 2023): 878. http://dx.doi.org/10.3390/w15050878.

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An applicable, high-volume, and sustainable water uptake technology can alleviate freshwater shortages, improve the energy utilization rate and promote the development of energy technology. Traditional seawater desalination, fog water, and dew collection are limited by the geographical environment, and the water resource transportation cost is high, or the water uptake volume is limited, so they cannot be used on a large scale. There are potential safety problems with wastewater reuse and recycled water. Atmospheric water harvesting technology uses energy for direct condensation or uses adsorbent to absorb water, which is characterized by strong sustainability, high applicability, decentralization, and stable water uptake. This study summarizes the working principle of mainstream atmospheric water harvesting technologies, mainly including condensation, absorption, and desorption water harvesting, and some active dew and fog collection technologies. It also theoretically analyzes the energy consumption of condensation and adsorption and desorption water harvesting technologies. Aiming at the problems of difficult condensing for direct condensation and long adsorption/desorption cycle of adsorption and desorption water harvesting, it summarizes the countermeasures of multi-stage condensation and multi-cycle adsorption and desorption. The development prospect of atmospheric water harvesting technologies is also discussed

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14

Knopf, Daniel A. y Markus Ammann. "Technical note: Adsorption and desorption equilibria from statistical thermodynamics and rates from transition state theory". Atmospheric Chemistry and Physics 21, n.º 20 (21 de octubre de 2021): 15725–53. http://dx.doi.org/10.5194/acp-21-15725-2021.

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Abstract. Adsorption and desorption represent the initial processes of the interaction of gas species with the condensed phase. They have important implications for evaluating heterogeneous (gas-to-solid) and multiphase chemical kinetics involved in catalysis; environmental interfaces; and, in particular, aerosol particles. When describing gas uptake, gas-to-particle partitioning, and the chemical transformation of aerosol particles, parameters describing adsorption and desorption rates are crucial to assessing the underlying chemical kinetics such as surface reaction and surface-to-bulk transfer. For instance, the desorption lifetime, in turn, depends on the desorption free energy which is affected by the chosen adsorbate model. To assess the impact of those conditions on desorption energy and, thus, desorption lifetime, we provide a complete classical and statistical thermodynamic treatment of the adsorption and desorption process considering transition state theory for two typically applied adsorbate models, the 2D ideal gas and the 2D ideal lattice gas, the latter being equivalent to Langmuir adsorption. Both models apply to solid and liquid substrate surfaces. We derive the thermodynamic and microscopic relationships for adsorption and desorption equilibrium constants, adsorption and desorption rates, first-order adsorption and desorption rate coefficients, and the corresponding pre-exponential factors. Although some of these derivations can be found in the literature, this study aims to bring all derivations into one place to facilitate the interpretation and analysis of the variables driving adsorption and desorption for their application in multiphase chemical kinetics. This exercise allows for a microscopic interpretation of the underlying processes including the surface accommodation coefficient and highlights the importance of the choice of adsorbate model and standard states when analyzing and interpreting adsorption and desorption processes. We demonstrate how the choice of adsorbate model affects equilibrium surface concentrations and coverages, desorption rates, and decay of the adsorbate species with time. In addition, we show how those results differ when applying a concentration- or activity-based description. Our treatment demonstrates that the pre-exponential factor can differ by orders of magnitude depending on the choice of adsorbate model with similar effects on the desorption lifetime, yielding significant uncertainties in the desorption energy derived from experimentally derived desorption rates. Furthermore, uncertainties in surface coverage and assumptions about standard surface coverage can lead to significant changes in desorption energies derived from measured desorption rates. Providing a comprehensive thermodynamic and microscopic representation aims to guide theoretical and experimental assessments of desorption energies and estimate potential uncertainties in applied desorption energies and corresponding desorption lifetimes important for improving our understanding of multiphase chemical kinetics.

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15

ZAKERI, KH y A. DASHTI. "MONTE CARLO SIMULATION OF TEMPERATURE-PROGRAMMED DESORPTION CO/Cu(110) AND CO2/Cu(100) SYSTEMS". Surface Review and Letters 11, n.º 02 (abril de 2004): 137–43. http://dx.doi.org/10.1142/s0218625x04006037.

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In this investigation, we have studied the kinetics and mechanism of desorption of CO from the Cu (110) surface using a new Monte Carlo simulation and putting emphasis on high order lateral interaction. According to our simulated TPD spectra, for β=10 K/s the maximum desorption rate occurs at Tm=218.6 K. Furthermore, analysis of simulated TPD spectra of CO desorption shows that it is strongly lateral-interactive and results an activation energy of CO desorption from Cu (110) that is Ed=66.6 Kj/mol. These simulated results are compared with other reported results and show excellent agreement. After that we have investigated the kinetics and mechanism of desorption of CO 2 from the Cu (100) surface using a Monte Carlo simulation. According to our simulated TPD spectra, for β=0.5 K/s the maximum desorption rate occurs at Tm=89.7 K. Analysis of simulated TPD spectra of CO 2 desorption shows that it is not strongly lateral-interactive and results in an activation energy of CO desorption from Cu (100) that is Ed=25.2 Kj/mol. Finally, the CO / Cu (110) system is compared with the CO 2/ Cu (100) system.

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16

Ramonova, Aljona, Tengiz Butkhuzi, Viktorija Abaeva, I. V. Tvauri, Soslan Khubezhov, Natalia Tsidaeva, Anatolij Turiev y Tamerlan T. Magkoev. "Low-Fluence Laser Induced Fragmentation and Desorption of 3,4,9,10-Perylenetetracarboxylic Dianhydride (PTCDA) Thin Film". Key Engineering Materials 543 (marzo de 2013): 30–34. http://dx.doi.org/10.4028/www.scientific.net/kem.543.30.

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Laser-induced fragmentation and desorption of fragments of PTCDA films vacuum-deposited on GaAs (100) substrate has been studied by time-of-flight (TOF) mass spectroscopy. The main effect caused by pulsed laser light irradiation (pulse duration: 10 ns, photon energy: 2.34 eV and laser fluence ranging from 0.5 to 7 mJ/cm2) is PTCDA molecular fragmentation and desorption of the fragments formed, whereas no desorption of intact PTCDA molecule was detected. Fragments formed are perylene core C20H8, its half C10H4, carbon dioxide, carbon monoxide and atomic oxygen. All desorbing fragments have essentially different kinetic energy. The mechanism of photoinduced molecular fragmentation and desorption is discussed.

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17

Kobayashi, Takane, Daniel Primetzhofer, Margareta Linnarsson y Anders Hallén. "Ion-stimulated desorption in the medium-energy regime". Japanese Journal of Applied Physics 53, n.º 6 (16 de mayo de 2014): 060305. http://dx.doi.org/10.7567/jjap.53.060305.

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18

Lebedev, V. I., V. V. Mizina, L. V. Blagina y A. A. Barannik. "Temperature-dependent activation energy for silicon desorption processes". Inorganic Materials 44, n.º 5 (mayo de 2008): 450–52. http://dx.doi.org/10.1134/s0020168508050026.

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19

Knizikevičius, R. "Comparison of methods for deriving desorption activation energy". Vacuum 115 (mayo de 2015): 58–60. http://dx.doi.org/10.1016/j.vacuum.2015.02.011.

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Knizikevičius, R. "Evaluation of desorption activation energy of SiCl2 molecules". Surface Science 531, n.º 2 (mayo de 2003): L347—L350. http://dx.doi.org/10.1016/s0039-6028(03)00509-0.

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Knizikevičius, R. "Evaluation of desorption activation energy of SiF4 molecules". Vacuum 68, n.º 1 (octubre de 2002): 29–30. http://dx.doi.org/10.1016/s0042-207x(02)00278-6.

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22

Ojha, Deepak K., Matthew J. Kale, Paul J. Dauenhauer, Alon McCormick y E. L. Cussler. "Desorption in Ammonia Manufacture from Stranded Wind Energy". ACS Sustainable Chemistry & Engineering 8, n.º 41 (20 de julio de 2020): 15475–83. http://dx.doi.org/10.1021/acssuschemeng.0c03154.

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Knizikevičius, R. "Evaluation of desorption activation energy of SiF2 molecules". Chemical Physics Letters 410, n.º 1-3 (julio de 2005): 177–78. http://dx.doi.org/10.1016/j.cplett.2005.05.068.

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Knizikevičius, R. "Evaluation of desorption activation energy of SiBr2 molecules". Chemical Physics Letters 512, n.º 4-6 (agosto de 2011): 188–89. http://dx.doi.org/10.1016/j.cplett.2011.07.044.

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Zvára, I. "Vacuum thermochromatography: diffusion approximation, evaluation of desorption energy". Journal of Radioanalytical and Nuclear Chemistry 299, n.º 3 (23 de enero de 2014): 1847–57. http://dx.doi.org/10.1007/s10967-014-2923-6.

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26

Nefliu, Marcela, Jonell N. Smith, Andre Venter y R. Graham Cooks. "Internal energy distributions in desorption electrospray ionization (DESI)". Journal of the American Society for Mass Spectrometry 19, n.º 3 (marzo de 2008): 420–27. http://dx.doi.org/10.1016/j.jasms.2007.11.019.

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Fain, B., V. Fleurov y S. H. Lin. "Intermolecular energy transfer in infrared-laser-induced desorption". Chemical Physics 122, n.º 1 (mayo de 1988): 17–28. http://dx.doi.org/10.1016/0301-0104(88)87255-0.

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Ghiaasiaan, S. M., A. T. Wassel y A. A. Pesaran. "Gas Desorption From Seawater in Open-Cycle Ocean Thermal Energy Conversion Barometric Upcomers". Journal of Solar Energy Engineering 112, n.º 3 (1 de agosto de 1990): 204–15. http://dx.doi.org/10.1115/1.2930481.

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Gas desorption from warm and cold seawater under open-cycle ocean thermal energy conversion (OC-OTEC) conditions is addressed in this paper. The desorption process of dissolved O2, N2, and CO2 in the barometric upcomers of an OTEC plant is simulated mathematically. The model considers the growth of bubbles originating in the ocean and bubbles formed in the upcomers. Bubble growth is induced by gas mass transfer and water evaporation at the bubble-liquid interface, as well as by the decreasing hydrostatic pressure. Heterogeneous nucleation at pipe wall crevices and on suspended particles in the water stream is also modeled. Bubble coalescence due to turbulent shear and differential buoyancy is simulated. The results generated show the deaeration efficiency as a function of flow and geometric parameters. The calculations show that gas desorption in the barometric upcomers can be appreciable. Such desorption is enhanced by increasing the concentration of the incoming and/or the heterogeneously formed bubbles. Results of existing experiments are discussed and predictions are shown for the selected test conditions.

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Yamaguchi, Masato, Ken Miyajima y Fumitaka Mafuné. "Desorption Energy of Oxygen Molecule from Anionic Gold Oxide Clusters, AunO2–, Using Thermal Desorption Spectrometry". Journal of Physical Chemistry C 120, n.º 40 (28 de septiembre de 2016): 23069–73. http://dx.doi.org/10.1021/acs.jpcc.6b08139.

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Wittkopf, H. "Calculation of desorption energy distribution applied to temperature programmed H2O desorption from silicate glass surface". Vacuum 37, n.º 11-12 (enero de 1987): 819–23. http://dx.doi.org/10.1016/0042-207x(87)90181-3.

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31

Liu, Yongfeng, Jianjiang Hu, Zhitao Xiong, Guotao Wu y Ping Chen. "Improvement of the hydrogen-storage performances of Li–Mg–N–H system". Journal of Materials Research 22, n.º 5 (mayo de 2007): 1339–45. http://dx.doi.org/10.1557/jmr.2007.0165.

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Li2MgN2H2 can reversibly store more than 5.5 wt% hydrogen. However, the high activation energy of hydrogen desorption poses a kinetic barrier for low-temperature operation. In this work, the composition of the Li–Mg–N–H system has been modified by the partial substitution of Mg or Li by Na. The changes in structure and hydrogen absorption/desorption kinetics have been investigated. It was found that the peak temperature for hydrogen desorption was decreased by ∼10 °C, and that the hydrogen absorption/desorption isotherms were also significantly changed. Furthermore, the activation energy calculated by the Kissinger’s approach was reduced after the substitution of Mg or Li by Na. In addition, the different dehydrogenation structures were detected at different molar ratios of Mg, Li, and Na.

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32

Checchetto, Riccardo, Daniele Rigotti, Alessandro Pegoretti y Antonio Miotello. "Chloroform desorption from poly(lactic acid) nanocomposites: a thermal desorption spectroscopy study". Pure and Applied Chemistry 92, n.º 3 (26 de marzo de 2020): 391–98. http://dx.doi.org/10.1515/pac-2018-1216.

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AbstractBiopolymer nanocomposites were prepared by solvent casting dispersing lauryl-functionalized cellulose nano-fibrils (CNF) in a poly(lactic acid) matrix (PLA). The release of residual chloroform (CHCl3) solvent molecules was studied by Thermal Desorption Spectroscopy (TDS) analysis. TDS spectra of the PLA matrix show a single desorption peak at TP = 393 K with FWHM ~10 K, compatible with a zero-order desorption kinetics. This narrow TDS peak was accurately reproduced assuming that: (i) the rate limiting step is given by the CHCl3 de-trapping from sites in the PLA matrix where residual solvent molecules form small aggregates and (ii) the activation energy for desorption linearly decreases from 1.19 eV for saturated traps to 1.11 eV when the traps occupancy by solvent molecules approaches zero. The balance energy term ϵD = −0.08 eV is due to the attractive interactions between trapped CHCl3 molecules. Adding CNF particles to the PLA matrix the zero-order peak shifts to lower temperatures and a second peak with FWHM ~60 K appears at higher temperatures. This second peak is compatible with a first-order desorption kinetics and is attributed to the release of dispersed CHCl3 molecules from trapping sites in PLA-CNF interface region. The obtained information are of interest for applications in food and electronic packaging and for the development of medical materials.

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33

Wang, Lei, Mohammad Saeed, Jianmin Luo, Anna Lee, Rowan Simonet, Zhao Sun, Nigel Walker et al. "Highly Efficient Removal of CO2 Using Water-Lean KHCO3/Isopropanol Solutions". Atmosphere 13, n.º 9 (17 de septiembre de 2022): 1521. http://dx.doi.org/10.3390/atmos13091521.

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The use of aqueous carbonate as an inorganic absorbent is not only inexpensive but also stable and environmentally friendly. However, the regeneration processes for aqueous carbonate sorbents require high regeneration heat duty; this energy intensity makes their wide utilization unaffordable. In this work, a low-temperature, energy-saving, and environmentally friendly carbon dioxide desorption method has been investigated in potassium bicarbonate-water-alcohol solutions. The addition of alcohol, particularly isopropanol, to the potassium bicarbonate-water solution can significantly increase carbon dioxide desorption capacity. The potassium bicarbonate-water-isopropanol solution used in this study (36 wt % isopropanol) resulted in 15.2 mmol of carbon dioxide desorption within 2400 s at 80 °C, which was 2000-fold higher than the potassium bicarbonate-water-solution. This research demonstrates a water-lean solvent-based carbon dioxide removal route with the potential to be economical, environmentally safe, and energy-efficient. CO2 sequestration, capture, and utilization technologies will play a key role in reducing CO2 emissions. The excellent desorption kinetics and relatively moderate desorption temperatures (80 °C) of water-lean solvent could help in reducing the cost of CO2 capture, particularly in terms of the heat demand at the regenerator.

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34

Nurul Aini, Olyvia Putri Wardhani y Iriany. "DESORPSI β-KAROTEN MINYAK KELAPA SAWIT (CRUDE PALM OIL) DARI KARBON AKTIF MENGGUNAKAN ISOPROPANOL". Jurnal Teknik Kimia USU 5, n.º 4 (24 de enero de 2017): 1–7. http://dx.doi.org/10.32734/jtk.v5i4.1547.

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The aim of the research is to study the ability of isopropyl alcohol in the desorption of β-carotene and to obtain kinetic model and desorption isoterm which is suitable in β-carotene desorption. The main material used were isopropyl alcohol and activated carbon containing β-carotene. The variabels used in this research are desorption temperature, activated carbon concentration and parameter observed is concentration of β-carotene in isopropyl alcohol. In the desorption process, activated carbon which adsorp β-carotene was soaked in isopropyl alcohol. To review the desorption kinetics, this research was carried out in various temperature such as 40 oC, 50 oC, and 60 oC. In desorption isoterm process is, various mass of activated carbon was used. Desorption process will be analyzed at spesified time. This research used the first order of desorption kinetics model. The desorption constant rate obtained for 40 oC, 50 oC, and 60 oC are 0,013, 0,014, and 0,036 minute-1 with activation energy is 0,226 kkal/mol. The maximum desorption percentage obtain is 41,94 %. The desorption isoterm model which fit with the β-carotene desorption was Langmuir isoterm model with constanta value 1,2077 L/mg and -0,2218.

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35

Lv, Peng Peng, Feng Wang, Yu Hai Guo y Hong Yan Tang. "CO₂ Desorption by Hydrophilic PTFE Hollow Fiber Membranes via a Membrane Flash Process". Key Engineering Materials 671 (noviembre de 2015): 293–99. http://dx.doi.org/10.4028/www.scientific.net/kem.671.293.

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In this study, hydrophilic PTFE hollow fiber membranes were prepared and applied for CO2 desorption via a membrane flash process, which is a new CO2 desorption process by utilizing waste thermal energy. The methyldiethanolamine was selected as the absorbent. Effects of the flashing temperature, flashing pressure, rich solution flow rate and MDEA concentration on CO2 release ratio and CO2 desorption flux were deeply investigated. The results show that flashing temperature is positive to the CO2 release ratio and CO2 desorption flux. However, the flashing pressure, rich solution flow rate and MDEA concentration are negative to the CO2 release ratio and CO2 desorption flux.

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36

Mehrabian, Hadi, Jacco H. Snoeijer y Jens Harting. "Desorption energy of soft particles from a fluid interface". Soft Matter 16, n.º 37 (2020): 8655–66. http://dx.doi.org/10.1039/d0sm01122c.

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37

Grajek, Henryk. "Regeneration of Adsorbents by the Use of Liquid, Subcritical and Supercritical Carbon Dioxide". Adsorption Science & Technology 18, n.º 4 (mayo de 2000): 347–71. http://dx.doi.org/10.1260/0263617001493486.

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The literature concerning the adsorption and desorption of environmental impurities from adsorbents by means of liquid, subcritical and supercritical carbon dioxide and the author's work on the subject have been reviewed. The influence of the adsorption and desorption temperature, the pressure and the density of the extraction solvent, the solubility of the adsorbate in the extraction solvent, the activation energy for adsorbate desorption and the particle size of the adsorbent on the adsorbate desorption efficiency by this method were discussed.

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38

Chaabouni, H., S. Diana, T. Nguyen y F. Dulieu. "Thermal desorption of formamide and methylamine from graphite and amorphous water ice surfaces". Astronomy & Astrophysics 612 (abril de 2018): A47. http://dx.doi.org/10.1051/0004-6361/201731006.

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Context. Formamide (NH2CHO) and methylamine (CH3NH2) are known to be the most abundant amine-containing molecules in many astrophysical environments. The presence of these molecules in the gas phase may result from thermal desorption of interstellar ices. Aims. The aim of this work is to determine the values of the desorption energies of formamide and methylamine from analogues of interstellar dust grain surfaces and to understand their interaction with water ice. Methods. Temperature programmed desorption (TPD) experiments of formamide and methylamine ices were performed in the sub-monolayer and monolayer regimes on graphite (HOPG) and non-porous amorphous solid water (np-ASW) ice surfaces at temperatures 40–240 K. The desorption energy distributions of these two molecules were calculated from TPD measurements using a set of independent Polanyi–Wigner equations. Results. The maximum of the desorption of formamide from both graphite and ASW ice surfaces occurs at 176 K after the desorption of H2O molecules, whereas the desorption profile of methylamine depends strongly on the substrate. Solid methylamine starts to desorb below 100 K from the graphite surface. Its desorption from the water ice surface occurs after 120 K and stops during the water ice sublimation around 150 K. It continues to desorb from the graphite surface at temperatures higher than160 K. Conclusions. More than 95% of solid NH2CHO diffuses through the np-ASW ice surface towards the graphitic substrate and is released into the gas phase with a desorption energy distribution Edes = 7460–9380 K, which is measured with the best-fit pre-exponential factor A = 1018 s−1. However, the desorption energy distribution of methylamine from the np-ASW ice surface (Edes = 3850–8420 K) is measured with the best-fit pre-exponential factor A = 1012 s−1. A fraction of solid methylamine monolayer of roughly 0.15 diffuses through the water ice surface towards the HOPG substrate. This small amount of methylamine desorbs later with higher binding energies (5050–8420 K) that exceed that of the crystalline water ice (Edes = 4930 K), which is calculated with the same pre-exponential factor A = 1012 s−1. The best wetting ability of methylamine compared to H2O molecules makes CH3NH2 molecules a refractory species for low coverage. Other binding energies of astrophysical relevant molecules are gathered and compared, but we could not link the chemical functional groups (amino, methyl, hydroxyl, and carbonyl) with the binding energy properties. Implications of these high binding energies are discussed.

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39

Xia, Qibin, Zhong Li, Hongxia Xi y Kefeng Xu. "Activation Energy for Dibenzofuran Desorption from Fe3+/TiO2 and Ce3+/TiO2 Photocatalysts Coated onto Glass Fibres". Adsorption Science & Technology 23, n.º 5 (junio de 2005): 357–66. http://dx.doi.org/10.1260/026361705774355469.

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In this work, TiO2, Fe3+/TiO2 and Ce3+/TiO2 photocatalytic films were respectively immobilized on glass fibres via the sol—gel technique to prepare supported photocatalysts. Temperature programmed desorption (TPD) experiments were conducted to measure the TPD curves for the removal of dibenzofuran from these photocatalysts, from which the activation energy for dibenzofuran desorption from the photocatalyst surfaces was estimated. The results showed that the activation energies for dibenzofuran desorption from the photocatalysts TiO2, Ce3+/TiO2 and Fe3+/TiO2 coated separately onto the glass fibres were 16.41 kJ/mol, 22.55 kJ/mol and 33.59 kJ/mol, respectively, while the hardness values of the ions Fe3+, Ce3+ and Ti4+ were respectively 13.1 eV, 11.9 eV and 10.6 eV. The data indicated that the use of Fe3+ or Ce3+ ions for doping a TiO2 photo-catalyst increased the local hardness of the doped TiO2 photocatalyst surface. This, in turn, increased the activation energy for the desorption of dibenzofuran from such a TiO2 photocatalyst surface.

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40

Khaisri, Sakarin, David deMontigny, Paitoon Tontiwachwuthikul y Ratana Jiraratananon. "Membrane contacting process for CO2 desorption". Energy Procedia 4 (2011): 688–92. http://dx.doi.org/10.1016/j.egypro.2011.01.106.

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41

Keuter, Philipp, Soheil Karimi Aghda, Denis Music, Pauline Kümmerl y Jochen M. Schneider. "Synthesis of Intermetallic (Mg1−x,Alx)2Ca by Combinatorial Sputtering". Materials 12, n.º 18 (18 de septiembre de 2019): 3026. http://dx.doi.org/10.3390/ma12183026.

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The synthesis–composition–structure relationship in the Mg–Ca–Al system is studied using combinatorial magnetron sputtering. With increasing deposition temperature, a drastic decrease in Mg concentration is obtained. This behavior can be understood based on density functional theory calculations yielding a desorption energy of 1.9 eV/atom for Mg from a hexagonal Mg nanocluster which is far below the desorption energy of Mg from a Mg2Ca nanocluster (3.4 eV/atom) implying desorption of excess Mg during thin film growth at elevated temperatures. Correlative structural and chemical analysis of binary Mg–Ca thin films suggests the formation of hexagonal Mg2Ca (C14 Laves phase) in a wide Mg/Ca range from 1.7 to 2.2, expanding the to date reported stoichiometry range. Pronounced thermally-induced desorption of Mg is utilized to synthesize stoichiometric (Mg1−x,Alx)2Ca thin films by additional co-sputtering of elemental Al, exhibiting a higher desorption energy (6.7 eV/atom) compared to Mg (3.4 eV/atom) from Mg2Ca, which governs its preferred incorporation during synthesis. X-ray diffraction investigations along the chemical gradient suggest the formation of intermetallic C14 (Mg1–x,Alx)2Ca with a critical aluminum concentration of up to 23 at.%. The introduced synthesis strategy, based on the thermally-induced desorption of weakly bonded species, and the preferential incorporation of strongly bonded species, may also be useful for solubility studies of other phases within this ternary system as well as for other intermetallics with weakly bonded alloying constituents.

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42

Brdaric, Tanja, Ljiljana Stamenkovic, Nikola Novakovic y Jasmina Grbovic-Novakovic. "Hydrogen desorption from nanostructured magnesium hydride composites". Chemical Industry 61, n.º 2 (2007): 71–74. http://dx.doi.org/10.2298/hemind0702071b.

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The influence of 3d transition metal addition (Fe, Co and Ni) on the desorption properties of magnesium hydride were studied. The ball milling of MgH2-3d metal blends was performed under Ar. Microstructural and morphological characterization were performed by XRD and SEM analysis, while the hydrogen desorption properties were investigated by DSC. The results show a strong correlation between the morphology and thermal stability of the composites. The complex desorption behavior (the existence of more than one desorption peak) was correlated with the dispersion of the metal additive particles that appear to play the main role in the desorption. The desorption temperature can be reduced by more than 100 degrees if Fe is added as additive. The activation energy for H2 desorption from the MgH2-Fe composite is 120 kJ/mol, implying that diffusion controls the dehydration process.

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43

KOŁASIŃSKI, KURT W. "DYNAMICS OF HYDROGEN INTERACTIONS WITH Si(100) AND Si(111) SURFACES". International Journal of Modern Physics B 09, n.º 21 (30 de septiembre de 1995): 2753–809. http://dx.doi.org/10.1142/s0217979295001038.

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Experimental and theoretical work probing the dynamics of dissociative adsorption and recombinative desorption of hydrogen at Si(100) and Si (111) surfaces is reviewed. Whereas molecular beam experiments demonstrate that molecular excitations do aid in overcoming a substantial activation barrier toward adsorption, desorbed molecules are found to have a total energy content only slightly above the equilibrium expectation at the surface temperature. A consistent interpretation of the ad/desorption dynamics is arrived at which requires neither a violation of microscopic reversibility nor defect-mediated processes. An essential element of this model is that surface atom relaxations play an essential role in the dynamics such that different portions of the potential energy hypersurface govern the results of adsorption and desorption experiments. The ‘lost’ energy, i.e. that portion of the activation energy not evident in the total energy of the desorbed molecules, is deposited in the surface coordinates where it is inaccessible to experiments that probe the desorbates final state.

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44

Tashlykova-Bushkevich, Iya I., Takahiro Shikagawa, Takayoshi Suzuki, Vasiliy G. Shepelevich y Goroh Itoh. "Effect of Cr and Zr Dopes on Hydrogen Behaviour in Rapidly Solidified Aluminium Foils". Materials Science Forum 638-642 (enero de 2010): 465–68. http://dx.doi.org/10.4028/www.scientific.net/msf.638-642.465.

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Hydrogen (H) behaviour in materials was investigated in rapidly solidified (RS) foils of pure aluminium (Al), Al-0.4 Cr and Al-0.25 Zr alloys (at %) by means of thermal desorption spectroscopy (TDS). In addition, Al-0.25; 0.3 Zr alloys were examined with respect to microstructure and its instability during the thermal process using SEM and microhardness measurements. The effect of dopes and heating rate on H desorption was summarized. The lowest energy desorption is attributed with significant thermal desorption peak which temperature was found is correlated with sample composition.

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45

Zhao, Dong Mei y Xue Peng Liu. "The Study of Iron Catalyst for Ammonia Synthesis in Chemical Engineering". Advanced Materials Research 577 (octubre de 2012): 97–100. http://dx.doi.org/10.4028/www.scientific.net/amr.577.97.

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The temperature programmed desorption technique is used to study the hydrogen adsorption on the catalytic surface of fused iron catalysts with different oxide precursors in chemical engineering. The different catalysts desorption active energy, desorped temperature and their amouts desorped have been attained. The desorption energies, desorped temperatures and desorption amounts have been related to the iron ratio (Fe2+/Fe3+). It is compared with the curve of ammonia synthesis activity against iron ratio. The inhibition of hydrogen in the ammonia synthesis reaction is verified, the adsorption intensity of hydrogen controls the inhibition to nitrogen adsorption

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46

Healey, F., R. N. Carter y A. Hodgson. "The recombinative desorption of D2 from Ag(111): temperature-programmed desorption and low energy electron diffraction". Surface Science 328, n.º 1-2 (abril de 1995): 67–79. http://dx.doi.org/10.1016/0039-6028(95)00023-2.

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47

Chilukuri, Bhaskar, Ursula Mazur y K. W. Hipps. "Cooperativity and coverage dependent molecular desorption in self-assembled monolayers: computational case study with coronene on Au(111) and HOPG". Physical Chemistry Chemical Physics 21, n.º 20 (2019): 10505–13. http://dx.doi.org/10.1039/c9cp01774g.

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Molecular desorption energy in non-covalent SAMs is conventionally determined to be a solitary value. To the contrary, we show that the desorption energies are variable, coverage dependent and cooperative using coronene adsorbate and HOPG, Au(111) substrates.

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48

Millar, Graeme J., David Newton, Graham A. Bowmaker y Ralph P. Cooney. "In situ FT-IR Investigation of Formic Acid Adsorption on Reduced and Reoxidized Copper Catalysts". Applied Spectroscopy 48, n.º 7 (julio de 1994): 827–32. http://dx.doi.org/10.1366/0003702944029893.

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An in situ infrared cell capable of studying reactions over heterogeneous catalysts in the temperature range 77 to 773 K has been designed. In particular, the adsorption of formic acid on a model Cu/SiO2 methanol synthesis catalyst was investigated. Exposure of a reduced copper surface to formic acid at 300 K resulted in the formation of both formic acid molecules, which were ligated to the copper catalyst, and chemisorbed bidentate copper formate species. Under temperature-programming conditions, the bidentate species displayed a maximum rate of desorption at 433 K, which correlates to a desorption activation energy of 120 kJ mol−1. In contrast, on the reoxidized catalyst, unidentate formate species were preferentially formed. These exhibited a maximum rate of desorption at a temperature of 408 K, and a desorption activation energy of 113 kJ mol−1. A mechanism was postulated to explain this behavior, and evidence was presented to show that useful kinetic data can be obtained for desorption from a catalyst in the form of a pressed disk.

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49

Peng, Tao, Yue Chen, Liya Wang, Dongmin Ma, Guofu Li, Weibo Li, Chao Zheng et al. "Mechanism of Methane Adsorption/Desorption in Low-Rank Vitrain and Durain Coal Affected by Pore Structure and Wettability: A Case Study in Dafosi Area, South Ordos Basin, China". Energies 15, n.º 14 (12 de julio de 2022): 5094. http://dx.doi.org/10.3390/en15145094.

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Water content and water–coal interface wettability are always the difficult issues of coalbed methane adsorption/desorption. In order to study the effects of the pore structure and wettability of different macro coal components on methane adsorption and desorption, we compared and analyzed the wettability difference between vitrain and durain, and revealed the influence of wettability on methane adsorption and desorption through a pore structure analysis, wettability measurements, an adsorption–desorption experiment and adsorption heat calculations under different conditions, taking the No. 4 coal in Dafosi Coal Mine of the Huanglong coalfield as the research object. The results show that both vitrain and durain are relatively hydrophilic substances. However, vitrain has a low ash content, high volatility, and less oxygen, and the pores are mainly semi-closed pores compared with dark coal. Vitrain also has poor connectivity, poor sorting, a small pore diameter, and a coarser surface, resulting in poor surface wettability. The large specific surface area (SSA) and relatively poor wettability of vitrain leads to more adsorption sites in methane, which makes the adsorption capacity of vitrain greater than that of durain, but the good pore connectivity of durain causes the strong desorption capacity of durain. The isosteric adsorption heat of the adsorption process is greater than that of the desorption process, indicating that there is a desorption hysteresis phenomenon which is essentially due to the lack of energy in desorption. Surfactants change the wettability of the coal surface, and different surfactants have different effects on methane adsorption and desorption. Relatively speaking, the methane desorption of coal samples treated with G502 and 6501 are better. The research results provide scientific reference for the study of gas–water transport in the desorption process of low-rank CBM, and provide evidence for the methane desorption model of vitrain and durain.

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ASHKENAZY, Y. y I. KELSON. "SITE AND INTERACTION DEPENDENCE OF NUCLEAR STIMULATED DESORPTION FROM STRUCTURED SURFACES". Surface Review and Letters 06, n.º 05 (octubre de 1999): 613–19. http://dx.doi.org/10.1142/s0218625x99000573.

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Molecular dynamics calculations of low energy Nuclear Stimulated Desorption (NSD) of 107 Cd from a palladium substrate are presented. The characteristics of the desorption probability are shown to be related both to the site occupied by the 107 Cd and to the adsorbate–substrate interaction. The quantitative implications of the theoretical calculations to a specific experimental scenario are discussed, based on preliminary measurements of 107 Cd desorption from palladium.

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