Статті в журналах: "Double Atom Catalyst"

1

Kim, Seung-hoon, Ho Chang Song, Sung Jong Yoo, Jonghee Han, Kwan-Young Lee, and Hyung Chul Ham. "Impact of the dopant-induced ensemble structure of hetero-double atom catalysts in electrochemical NH₃ production." Journal of Materials Chemistry A 10, no. 11 (2022): 6216–30. http://dx.doi.org/10.1039/d1ta08358a.

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Compared to Ru single atom catalyst, hetero-RuM (M = Fe, Os, and Ir) double atom catalysts showed improved N2RR activity with the help of dxz and dxy bonding orbital, caused by strain, dopant and configurational effects.

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2

Wu, Donghai, Bingling He, Yuanyuan Wang, Peng Lv, Dongwei Ma, and Yu Jia. "Double-atom catalysts for energy-related electrocatalysis applications: a theoretical perspective." Journal of Physics D: Applied Physics 55, no. 20 (January 31, 2022): 203001. http://dx.doi.org/10.1088/1361-6463/ac4b56.

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Abstract Due to the excellent activity, selectivity, and stability, atomically dispersed metal catalysts with well-defined structures have attracted intensive research attention. As the extension of single-atom catalyst, double-atom catalyst (DAC) featuring with the metal dimer anchored on a suitable substrate has recently emerged as a research focus for the energy-related electrocatalysis reactions. Due to the flexible dual-metal sites and the synergetic effect between the two metal atoms in DACs, there are more possibilities to adjust their geometrical configurations and electronic structures. The wide tunability of the active sites could offer more opportunities to optimize the binding strength of the reaction intermediates and thus the catalytic activity and/or selectivity of chemical reactions. Moreover, the neighboring metal sites provide a platform to perform more complex electrocatalysis reaction involving the chemical bond coupling. This review aims to summarize the recent advance in theoretical research on DACs for diverse energy-related electrocatalytic reactions. It starts with a brief introduction to DACs. Then an overview of the main experimental synthesis strategies of DACs is provided. Emphatically, the catalytic performance together with the underlying mechanism of the different electrocatalytic reactions, including nitrogen reduction reaction, carbon dioxide reduction reaction, oxygen reduction reaction, and oxygen and hydrogen evolution reactions, are highlighted by discussing how the outstanding attributes mentioned above affect the reaction pathway, catalytic activity, and product selectivity. Finally, the opportunities and challenges for the development of DACs are prospected to shed fresh light on the rational design of more efficient catalysts at the atomic scale in the future.

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3

Hao, Zhuo, Yangyang Ma, Yisong Chen, Pei Fu, and Pengyu Wang. "Non-Noble Metal Catalysts in Cathodic Oxygen Reduction Reaction of Proton Exchange Membrane Fuel Cells: Recent Advances." Nanomaterials 12, no. 19 (September 24, 2022): 3331. http://dx.doi.org/10.3390/nano12193331.

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The oxygen reduction reaction (ORR) is one of the crucial energy conversion reactions in proton exchange membrane fuel cells (PEMFCs). Low price and remarkable catalyst performance are very important for the cathode ORR of PEMFCs. Among the various explored ORR catalysts, non-noble metals (transition metal: Fe, Co, Mn, etc.) and N co-doped C (M–N–C) ORR catalysts have drawn increasing attention due to the abundance of these resources and their low price. In this paper, the recent advances of single-atom catalysts (SACs) and double-atom catalysts (DACs) in the cathode ORR of PEMFCs is reviewed systematically, with emphasis on the synthesis methods and ORR performance of the catalysts. Finally, challenges and prospects are provided for further advancing non-noble metal catalysts in PEMFCs.

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4

Wang, Yun, and Lihua Kang. "Selective Hydrogenation of Acetylene Catalysed by a B12N12 Cluster Doped with a Single Nickel Atom: A DFT Study." Catalysts 10, no. 1 (January 13, 2020): 115. http://dx.doi.org/10.3390/catal10010115.

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To obtain a catalyst based on a non-precious metal that can replace traditional palladium-based selective catalysts of acetylene hydrogenation, the catalytic performances of two different configurations of a B12N12 cluster doped with a single nickel atom were studied by a density functional theory computational approach. After analysing the effect that the adsorption of reactants onto the clusters has on the reaction path, we determined the lowest energy path for the acetylene double hydrogenation. Comparing the acetylene hydrogenation activities and ethylene product selectivities of the B11N12Ni and B12N11Ni clusters, which have different doping sites, we determined the activities of these two catalysts to be similar to each other; however, the B11N12Ni cluster was calculated to have higher selectivity for ethylene as a product. This difference may be related to the moderate adsorption of hydrogen and acetylene on the B11N12Ni cluster. As a new type of nickel-based single-atom catalyst, B11N12Ni clusters may have research value in the selective hydrogenation of acetylene.

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5

Mark, Brian L., and Michael NG James. "Anchimeric assistance in hexosaminidases." Canadian Journal of Chemistry 80, no. 8 (August 1, 2002): 1064–74. http://dx.doi.org/10.1139/v02-130.

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Configuration retaining glycosidases catalyse the hydrolysis of glycosidic bonds via a double displacement mechanism, typically involving two key active site carboxyl groups (Glu or Asp). One of the enzymic carboxyl groups functions as a general acidbase catalyst, the other acts as a nucleophile. Alternatively, configuration-retaining hexosaminidases from the sequence-related glycosidase families 18, 20, and 56 lack a suitably positioned enzymic nucleophile; instead, they use the carbonyl oxygen atom of the neighbouring C2-acetamido group of the substrate. The carbonyl oxygen atom of the 2-acetamido group provides anchimeric assistance to the enzyme catalyzed reaction by acting as an intramolecular nucleophile, attacking the anomeric center and forming a cyclized oxazolinium ion intermediate that is stereochemically equivalent to the glycosylenzyme intermediate formed in the "normal" double displacement mechanism. Although there is little sequence similarity between families 18, 20, and 56 hexosaminidases, X-ray crystallographic studies demonstrate that they have evolved similar catalytic domains and active site architectures that are designed to distort the bound substrate so that the C2-acetamido group can become appropriately positioned to participate in catalysis. The substrate distortion allows for a substrate-assisted catalytic reaction that displays all the general characteristics of the classic double-displacement mechanism including the formation of a covalent intermediate.Key words: glycoside hydrolase, hexosaminidase, glycosidase, substrate-assisted catalysis, anchimeric assistance.

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6

Bai, Lichen, Chia-Shuo Hsu, Duncan T. L. Alexander, Hao Ming Chen, and Xile Hu. "A Cobalt–Iron Double-Atom Catalyst for the Oxygen Evolution Reaction." Journal of the American Chemical Society 141, no. 36 (August 16, 2019): 14190–99. http://dx.doi.org/10.1021/jacs.9b05268.

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7

Dinamarca, Robinson, Verónica Valles, Brenda Ledesma, Cristian H. Campos, Gina Pecchi, and Andrea Beltramone. "Magnetic Fe3O4@SiO2–Pt and Fe3O4@SiO2–Pt@SiO2 Structures for HDN of Indole." Materials 12, no. 23 (November 24, 2019): 3878. http://dx.doi.org/10.3390/ma12233878.

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The effect of a second porous SiO2 shell in the activity and selectivity of the Fe3O4@SiO2–Pt catalyst in the hydrodenitrogenation of indole is reported. The double Fe3O4@SiO2–Pt@SiO2 structure was prepared by coating Fe3O4 nanoparticles with tetraethyl orthosilicate (TEOS) with a further impregnation of 1.0 wt.% of Pt on the (3-aminopropyl)triethoxysilane functionalized Fe3O4@SiO2 structures. The second porous SiO2 shell, obtained by using a hexadecyltrimethylammonium bromide (CTAB) template, covered the Fe3O4@SiO2–Pt catalyst with a well-defined and narrow pore-sized distribution. The full characterization by TEM, inductively coupled plasma-optical emission spectroscopy (ICP-OES), XRD, and N2 adsorption isotherm at 77 K and vibrating sample magnetometry (VSM) of the catalysts indicates homogeneous core@shell structures with a controlled nano-size of metallic Pt. A significant effect of the double SiO2 shell in the catalytic performance was demonstrated by both a higher activity to eliminate the nitrogen atom of the indole molecule present in model liquid fuel and the improvement of the catalytic stability reaching four consecutive reaction cycles with only a slight conversion level decrease.

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8

Yu, Linke, and Fengyu Li. "Pt2 Dimer Anchored Vertically in Defective BN Monolayer as an Efficient Catalyst for N2 Reduction: A DFT Study." Catalysts 12, no. 11 (November 8, 2022): 1387. http://dx.doi.org/10.3390/catal12111387.

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The electrochemical nitrogen reduction reaction (NRR) using clean energy is considered a promising alternative to the conventional Haber–Bosch process; however, developing a highly active electrocatalyst is still a great challenge. In this study, ten metal dimers anchored in a defective boron nitride (BN) monolayer as double-atom catalysts (DACs) with reverse sandwich structures were screened for their stability and catalytic activity towards NRR by density functional theory (DFT) calculations. Among them, three DACs (Rh2⊥vb-BN, Pt2⊥vb-BN and Rh2⊥vn-BN) were confirmed to be stable and have high promise as NRR electrocatalysts, and Pt2⊥vb-BN particularly distinguishes itself due to its very low limiting potential (−0.06 V). In addition, the electrocatalytic performance of all three DACs prevailed over that of their single-atom catalyst counterparts. We believe that the unique conformation of the reverse sandwich structure has impressive potential for the development of DACs, and we hope that our study provides a new design strategy for DACs for NRR and beyond.

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9

Cheng, Yu-Wei, Tar-Hwa Hsieh, Yu-Chang Huang, Po-Hao Tseng, Yen-Zen Wang, Ko-Shan Ho, and Yue-Jie Huang. "Calcined Co(II)-Chelated Polyazomethine as Cathode Catalyst of Anion Exchange Membrane Fuel Cells." Polymers 14, no. 9 (April 27, 2022): 1784. http://dx.doi.org/10.3390/polym14091784.

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Polyazomethine (PAM) prepared from the polycondensation between p-phenylene diamine (PDA) and p-terephthalaldehyde (PTAl) via Schiff reaction can physically crosslink (complex) with Co ions. Co-complexed PAM (Co-PAM) in the form of gel is calcined to become a Co, N-co-doped carbonaceous matrix (Co-N-C), acting as cathode catalyst of an anion exchange membrane fuel cell (AEMFC). The obtained Co-N-C catalyst demonstrates a single-atom structure with active Co centers seen under the high-resolution transmission electron microscopy (HRTEM). The Co-N-C catalysts are also characterized by XRD, SEM, TEM, XPS, BET, and Raman spectroscopy. The Co-N-C catalysts demonstrate oxygen reduction reaction (ORR) activity in the KOH(aq) by expressing an onset potential of 1.19–1.37 V vs. RHE, a half wave potential of 0.70–0.92 V, a Tafel slope of 61–89 mV/dec., and number of exchange electrons of 2.48–3.79. Significant ORR peaks appear in the current–voltage (CV) polarization curves for the Co-N-C catalysts that experience two-stage calcination higher than 900 °C, followed by double acid leaching (CoNC-1000A-900A). The reduction current of CoNC-1000A-900A is comparable to that of commercial Pt-implanted carbon (Pt/C), and the max power density of the single cell using CoNC-1000A-900A as cathode catalyst reaches 275 mW cm−2.

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10

Khlebnikov, Alexander, Vladimir Bodunov, Ekaterina Galenko, Alexey Galenko, and Mikhail Novikov. "Synthesis of Substituted Indole-3-carboxylates by Iron(II)-Catalyzed Domino Isomerization of 3-Alkyl/aryl-4-aryl-5-methoxyisoxazoles." Synthesis 50, no. 14 (May 29, 2018): 2784–98. http://dx.doi.org/10.1055/s-0036-1591576.

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The iron(II)-catalyzed domino isomerization of 3-alkyl/aryl-4-arylisoxazoles provides a selective access to a wide range of structurally diverse highly substituted indole-3-carboxylates. The operational simplicity, high atom efficiency, and the use of stable starting materials and an inexpensive and low-toxicity catalyst are some of the attractive features of this tandem double ring-opening–ring-closure strategy.

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11

Freindorf, Marek, and Elfi Kraka. "Mechanistic Details of the Sharpless Epoxidation of Allylic Alcohols—A Combined URVA and Local Mode Study." Catalysts 12, no. 7 (July 18, 2022): 789. http://dx.doi.org/10.3390/catal12070789.

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In this work, we investigated the catalytic effects of a Sharpless dimeric titanium (IV)–tartrate–diester catalyst on the epoxidation of allylalcohol with methyl–hydroperoxide considering four different orientations of the reacting species coordinated at the titanium atom (reactions R1–R4) as well as a model for the non-catalyzed reaction (reaction R0). As major analysis tools, we applied the URVA (Unified Reaction Valley Approach) and LMA (Local Mode Analysis), both being based on vibrational spectroscopy and complemented by a QTAIM analysis of the electron density calculated at the DFT level of theory. The energetics of each reaction were recalculated at the DLPNO-CCSD(T) level of theory. The URVA curvature profiles identified the important chemical events of all five reactions as peroxide OO bond cleavage taking place before the TS (i.e., accounting for the energy barrier) and epoxide CO bond formation together with rehybridization of the carbon atoms of the targeted CC double bond after the TS. The energy decomposition into reaction phase contribution phases showed that the major effect of the catalyst is the weakening of the OO bond to be broken and replacement of OH bond breakage in the non-catalyzed reaction by an energetically more favorable TiO bond breakage. LMA performed at all stationary points rounded up the investigation (i) quantifying OO bond weakening of the oxidizing peroxide upon coordination at the metal atom, (ii) showing that a more synchronous formation of the new CO epoxide bonds correlates with smaller bond strength differences between these bonds, and (iii) elucidating the different roles of the three TiO bonds formed between catalyst and reactants and their interplay as orchestrated by the Sharpless catalyst. We hope that this article will inspire the computational community to use URVA complemented with LMA in the future as an efficient mechanistic tool for the optimization and fine-tuning of current Sharpless catalysts and for the design new of catalysts for epoxidation reactions.

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12

Yang, Weijie, Binghui Zhou, Yongqian Zhang, Jianuo Ren, Chongchong Wu, Ian D. Gates, Yanfeng Liu, and Zhengyang Gao. "A novel low-temperature Fe-Fe double-atom catalyst for a “fast SCR” reaction." Molecular Catalysis 533 (December 2022): 112769. http://dx.doi.org/10.1016/j.mcat.2022.112769.

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13

Dai, Guoliang, Lei Chen, and Xin Zhao. "Tungsten-Embedded Graphene: Theoretical Study on a Potential High-Activity Catalyst toward CO Oxidation." Materials 11, no. 10 (September 28, 2018): 1848. http://dx.doi.org/10.3390/ma11101848.

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The oxidation mechanism of CO on W-embedded graphene was investigated by M06-2X density functional theory. Two models of tungsten atom embedded in single and double vacancy (W-SV and W-DV) graphene sheets were considered. It was found that over W-SV-graphene and W-DV-graphene, the oxidation of CO prefers to Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanism, respectively. The two surfaces exhibit different catalytic activity during different reaction stages. The present results imply that W-embedded graphene is a promising catalyst for CO oxidation, which provides a useful reference for the design of a high-efficiency catalyst in detecting and removing of toxic gases.

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14

Liu, Yiwen, Mengqi Liao, Yuting Hu, Tae-Gwan Lee, Ravindranadh Koutavarapu, Shaik Gouse Peera, and Chao Liu. "Density Functional Theory Study of Oxygen Evolution Reaction Mechanism on Rare Earth Sc-Doped Graphene." Batteries 9, no. 3 (March 17, 2023): 175. http://dx.doi.org/10.3390/batteries9030175.

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The development of a stable catalyst with excellent catalytic performance for the oxygen evolution reaction (OER) in alkaline environments is a key reaction in various electrochemical technologies. In this work, single-atom catalysts (SACs) systems in which scandium (Sc), a rare earth metal, with different N/C coordination environments (ScNxC3−x@SACs and ScNxC4−x@SACs of Sc) were systematically studied with the help of density functional theory (DFT) calculations. The results of the structural thermodynamic stability analysis indicated that the ScNxC3−x@SACs and ScNxC4−x@SACs systems are more stable with increasing N atom doping concentration around Sc. The ScN3, ScN3C, and ScN4 with better stability were selected as the objects of subsequent research. However, ScN3 and ScN4 form Sc(OH)2N3 and Sc(OH)2N4 structures with double-hydroxyl groups as ligands because of the strong adsorption of OH species, whereas the strong adsorption of OH species by ScN3C causes structural instability. Here, the overpotential (η) of Sc(OH)2N3 was 1.03 V; Sc(OH)2N4 had two reaction paths and the η of path 1 was 0.80 V, which was 0.30 V lower than that of path 2. Therefore, Sc(OH)2N4 can be used as a stable and promising OER catalyst with easy desorption of O2 and good cycle performance. The hydroxyl ligand modification of Sc-NxC3−x@SACs and Sc-NxC4−x@SACs provides a method for studying the catalytic performance of other rare earth elements.

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Mironenko, Roman M., Elina R. Saybulina, Liudmila N. Stepanova, Tatiana I. Gulyaeva, Mikhail V. Trenikhin, Konstantin S. Rodygin, and Valentine P. Ananikov. "Sustainable Hydrogenation of Vinyl Derivatives Using Pd/C Catalysts." Catalysts 11, no. 2 (January 28, 2021): 179. http://dx.doi.org/10.3390/catal11020179.

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The hydrogenation of unsaturated double bonds with molecular hydrogen is an efficient atom-economic approach to the production of a wide range of fine chemicals. In contrast to a number of reducing reagents typically involved in organic synthesis, hydrogenation with H2 is much more sustainable since it does not produce wastes (i.e., reducing reagent residues). However, its full sustainable potential may be achieved only in the case of easily separable catalysts and high reaction selectivity. In this work, various Pd/C catalysts were used for the liquid-phase hydrogenation of O-, S-, and N-vinyl derivatives with molecular hydrogen under mild reaction conditions (room temperature, pressure of 1 MPa). Complete conversion and high hydrogenation selectivity (>99%) were achieved by adjusting the type of Pd/C catalyst. Thus, the proposed procedure can be used as a sustainable method for vinyl group transformation by hydrogenation reactions. The discovery of the stability of active vinyl functional groups conjugated with heteroatoms (O, S, and N) under hydrogenation conditions over Pd/C catalysts opens the way for many useful transformations.

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16

Liu, Fan, Ning Yan, Guangqi Zhu, Zigeng Liu, Shenqian Ma, Guolei Xiang, Songrui Wang, Xingjiang Liu, and Wei Wang. "Fe–N–C single-atom catalysts with an axial structure prepared by a new design and synthesis method for ORR." New Journal of Chemistry 45, no. 29 (2021): 13004–14. http://dx.doi.org/10.1039/d1nj01380g.

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FePc powder sublimates losing H atoms to form unstable fragments at 450 °C which self-assemble to form units with a double-layer structure. The self-assembly units are driven by argon gas at 70 °C to where the substrate is located and crystallize to form Fe-N5/C@G catalyst.

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17

Zeng, Xianshi, Chuncai Xiao, Luliang Liao, Zongxing Tu, Zhangli Lai, Kai Xiong, and Yufeng Wen. "Two-Dimensional (2D) TM-Tetrahydroxyquinone Metal–Organic Framework for Selective CO2 Electrocatalysis: A DFT Investigation." Nanomaterials 12, no. 22 (November 17, 2022): 4049. http://dx.doi.org/10.3390/nano12224049.

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The resource utilization of CO2 is one of the essential avenues to realize the goal of “double carbon”. The metal–organic framework (MOF) has shown promising applications in CO2 catalytic reduction reactions due to its sufficient pore structure, abundant active sites and functionalizability. In this paper, we investigated the electrocatalytic carbon dioxide reduction reactions of single-atom catalysts created by MOF two-dimensional coordination network materials constructed from transition metal-tetrahydroxybenzoquinone using density function theory calculations. The results indicate that for 10 transition metals, TM-THQ single levels ranging from Sc to Zn, the metal atom binding energy to the THQ is large enough to allow the metal atoms to be stably dispersed in the THQ monolayer. The Ni-THQ catalyst does not compete with the HER reaction in an electrocatalytic CO2 reduction. The primary product of reduction for Sc-THQ is HCOOH, but the major product of Co-THQ is HCHO. The main product of Cu-THQ is CO, while the main product of six catalysts, Ti, V, Cr, Mn, Fe, and Zn, is CH4. The limit potential and overpotential of Ti-THQ are the highest, 1.043 V and 1.212 V, respectively. The overpotentials of the other monolayer catalysts ranged from 0.172 to 0.952 V, and they were all relatively low. Therefore, we forecast that the TM-HQ monolayer will show powerful activity in electrocatalytic carbon dioxide reduction, making it a prospective electrocatalyst for carbon dioxide reduction.

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18

Guillén, Luis G., Lioudmila Fomina, and Roberto Salcedo. "Capture and Reaction of CO2 and H2 Catalyzed by a Complex of Coronene: A Computational Study." Physchem 3, no. 3 (August 22, 2023): 342–54. http://dx.doi.org/10.3390/physchem3030024.

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An organometallic complex of coronene (Cor) and chromium (Cr) was designed and used as a catalyst in a simulated process in which a CO2 molecule is captured, activated, and then reacts with a hydrogen molecule (H2) to yield formic acid (HCOOH). The structural characteristics and local aromaticity are due to the similarity in the binding scheme with the bis(benzene)chromium (Cr-Bz2). Such a molecular fragment, referred to here as a “Clar’s site”, involves a single chromium atom that binds to CO2 by transferring electron density through backdonation. Therefore, the capture of CO2 outside the Cr3-Cor2 complex allows for the carrying out of a hydrogenation process that involves the breaking of one of the C−O bonds, the double addition of hydrogen, the formation of HCOOH and its release, regenerating the structure of the Cr3-Cor2 complex. The thermodynamic and kinetic results of this reaction are analyzed, as well as the nature of the orbitals and the relevant interactions of this process. This work explores a new concept for the creation of single atom catalysts (SACs), taking advantage of the high electron density around the metallic center and the sandwich architecture, having shown that it can perform the catalytic reduction of CO2.

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19

Bruneau, Christian, Christophe Darcel, and Pierre H. Dixneut. "Selective Palladium-Catalyzed Transformations of Cyclic Alk-2- ynyl Carbonates." Current Organic Chemistry 1, no. 3 (September 1997): 197–218. http://dx.doi.org/10.2174/1385272801666220124184425.

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Cyclic alk-2-ynyl carbonates, easily prepared from propargylic alcohols and carbon dioxide without phosgene derivatives, are useful synthetic substrates. Their activation with suitable palladium catalyst precursors leads to reactive zwitterionic allenyl palladium species and offers straightforward routes to functional a-allenols derivatives upon hydrogenolysis, coupling with terminal alkynes and monocarbonylation. The specificity of these cyclic carbonates as compared to acyclic propargylic derivatives, due to the presence of the reactive homopropargylic oxygen atom, is evidenced by the synthesis of oxygenated heterocycles resulting from double carbonylation, and dihydrofurans formed by coupling with electron deficient olefins.

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Li, Qianyu, Junhui Zhou, Didi Li, and Zhimin Ao. "Understanding the structure–activity relationships of different double atom catalysts from density functional calculations: three general rules for efficient CO oxidation." Journal of Materials Chemistry A 10, no. 16 (2022): 9025–36. http://dx.doi.org/10.1039/d2ta00709f.

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21

Jiang, Quanguo, Di Xiao, Hao Dong, Yuqing Wu, and Zhimin Ao. "Effects of carbon vacancies on the CO oxidation on Cu double atom catalyst supported by graphene." Surfaces and Interfaces 41 (October 2023): 103312. http://dx.doi.org/10.1016/j.surfin.2023.103312.

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22

Staal, Oetze K. B., Dirk J. Beetstra, Andries P. Jekel, Bart Hessen, Jan H. Teuben, Petr Štěpnička, Róbert Gyepes, Michal Horáček, Jiří Pinkas, and Karel Mach. "Polymerization of Propene with Modified Constrained Geometry Complexes. Double-Bond Isomerization in Pendant Alkenyl Groups Attached to Cyclopentadienyl Ligands." Collection of Czechoslovak Chemical Communications 68, no. 6 (2003): 1119–30. http://dx.doi.org/10.1135/cccc20031119.

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Polymerization of propene with dimethylsilylene-bridged (amidocyclopentadienyl)dichlorotitanium(IV) complexes [TiCl2{η5-1-(t-BuSiMe2N-κN)-2,3,4-Me3-5-R-C5}], where R = Me (1), H (2), Ph (3), 4-fluorophenyl (4), but-2-en-2-yl (5), and butyl (6), combined with excess methylaluminoxane revealed a moderate effect of the substituent R on the catalyst activity and the molecular weight of polypropene. The asymmetric substitution in the position adjacent to the bridging carbon atom resulted in polymer yields decreasing in the order 1 > 6 > 3 ≈ 5 > 4 > 2 while polymers with the molecular weights (Mw) close to 2.5 × 105 for 1, 3, and 4, 1.5 × 105 for 5 and 6, and 7.5 × 104 for 2 were obtained. The 13C NMR analysis of the polymers has shown that atactic polypropene is slightly enriched with syndiotactic triads for all the catalysts. Investigation of the crystal structure of 5 by X-ray crystallography revealed that the double bond in but-3-en-2-yl had shifted to an internal position to give the isomeric, but-2-en-2-yl-substituted complex. Likewise, the spectroscopic data for complex 7 prepared from the ligand containing but-3-en-1-yl substituent, indicate the absence of terminal double bond.

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23

Kim, Yujin, Sang Eon Jun, Goeun Lee, Seunghoon Nam, Ho Won Jang, Sun Hwa Park, and Ki Chang Kwon. "Recent Advances in Water-Splitting Electrocatalysts Based on Electrodeposition." Materials 16, no. 8 (April 12, 2023): 3044. http://dx.doi.org/10.3390/ma16083044.

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Green hydrogen is being considered as a next-generation sustainable energy source. It is created electrochemically by water splitting with renewable electricity such as wind, geothermal, solar, and hydropower. The development of electrocatalysts is crucial for the practical production of green hydrogen in order to achieve highly efficient water-splitting systems. Due to its advantages of being environmentally friendly, economically advantageous, and scalable for practical application, electrodeposition is widely used to prepare electrocatalysts. There are still some restrictions on the ability to create highly effective electrocatalysts using electrodeposition owing to the extremely complicated variables required to deposit uniform and large numbers of catalytic active sites. In this review article, we focus on recent advancements in the field of electrodeposition for water splitting, as well as a number of strategies to address current issues. The highly catalytic electrodeposited catalyst systems, including nanostructured layered double hydroxides (LDHs), single-atom catalysts (SACs), high-entropy alloys (HEAs), and core-shell structures, are intensively discussed. Lastly, we offer solutions to current problems and the potential of electrodeposition in upcoming water-splitting electrocatalysts.

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Fukusumi, Takanori, Natsuki Takei, Yubi Tateno, Takuya Aoki, Ai Ando, Kouhei Kozakai, Hiroko Shima, et al. "Ene-thiol reaction of C3-vinylated chlorophyll derivatives in the presence of oxygen: synthesis of C3-formyl-chlorins under mild conditions." Journal of Porphyrins and Phthalocyanines 17, no. 12 (December 2013): 1188–95. http://dx.doi.org/10.1142/s1088424613500983.

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Reactions of thiol with the C 3-vinyl group of various chlorophyll (Chl) derivatives were examined. The reactions resemble thiol-olefin co-oxidation, except that the vinyl C = C double bond was cleaved to afford a formyl group without any transition metal catalyst, and that the simple anti-Markovnikov adduct of thiol to olefin was obtained as a minor product. Peripheral substituents of Chl derivatives little affected the reaction, while the central metal atom of the chlorin macrocycle influenced the composition of the products. Oxygen and acid dissolved in the reaction mixture can facilitate the oxidation. Sufficiently mild conditions in this regioselective oxidation at the C 31-position are significant in bioorganic chemistry.

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Huang, Bin, Yifan Wu, Yaorong Luo, and Naigen Zhou. "Double atom-anchored Defective Boron Nitride catalyst for efficient electroreduction of CO2 to CH4: A first principles study." Chemical Physics Letters 756 (October 2020): 137852. http://dx.doi.org/10.1016/j.cplett.2020.137852.

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26

Zhao, Meiqi, Haoran Liu, Hongwei Zhang, Wen Chen, Hanqin Sun, Zhenhua Wang, Biao Zhang, et al. "A pH-universal ORR catalyst with single-atom iron sites derived from a double-layer MOF for superior flexible quasi-solid-state rechargeable Zn–air batteries." Energy & Environmental Science 14, no. 12 (2021): 6455–63. http://dx.doi.org/10.1039/d1ee01602d.

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27

Matsunami, Asuka, Shigeki Kuwata, and Yoshihito Kayaki. "Regioselective Transfer Hydrogenative Defluorination of Polyfluoroarenes Catalyzed by Bifunctional Azairidacycle." Organics 3, no. 3 (June 22, 2022): 150–60. http://dx.doi.org/10.3390/org3030012.

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The catalytic hydrodefluorination (HDF) with a bifunctional azairidacycle using HCOOK was examined for cyano- and chloro-substituted fluoroarenes, including penta- and tetrafluorobenzonitriles, tetrafluoroterephthalonitrile, tetrafluorophthalonitrile, 3-chloro-2,4,5,6-tetrafluoropyridine, and 4-cyano-2,3,5,6-tetrafluoropyridine. The reaction was performed in the presence of a controlled amount of HCOOK with a substrate/catalyst ratio (S/C) of 100 in a 1:1 mixture of 1,2-dimethoxyethane (DME) and H2O at an ambient temperature of 30 °C to obtain partially fluorinated compounds with satisfactory regioselectivities. The C–F bond cleavage proceeded favorably at the para position of substituents other than fluorine, which is in consonance with the nucleophilic aromatic substitution mechanism. In the HDF of tetrafluoroterephthalonitrile and 4-cyano-2,3,5,6-tetrafluoropyridine, which do not contain a fluorine atom at the para position of the cyano group, the double defluorination occurred solely at the 2- and 5-positions, as confirmed by X-ray crystallography. The HDF of 3-chloro-2,4,5,6-tetrafluoropyridine gave preference to the C–F bond cleavage over the C–Cl bond cleavage, unlike the dehalogenation pathway via electron-transfer radical anion fragmentation. In addition, new azairidacycles with an electron-donating methoxy substituent on the C–N chelating ligand were synthesized and served as a catalyst precursor (0.2 mol%) for the transfer hydrogenative defluorination of pentafluoropyridine, leading to 2,3,5,6-tetrafluoropyridine with up to a turnover number (TON) of 418.

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28

Yang, Weijie, Jianuo Ren, Jiajia Li, Hanwen Zhang, Kai Ma, Qingwu Wang, Zhengyang Gao, Chongchong Wu, and Ian D. Gates. "A novel Fe-Co double-atom catalyst with high low-temperature activity and strong water-resistant for O3 decomposition: A theoretical exploration." Journal of Hazardous Materials 421 (January 2022): 126639. http://dx.doi.org/10.1016/j.jhazmat.2021.126639.

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29

Mahpudz, Aishah, Siu Ling Lim, Hitoshi Inokawa, Katsuki Kusakabe, and Ryuichi Tomoshige. "Layered double hydroxide supported cobalt nanocluster: size control and the effect in catalytic hydrogen generation." E3S Web of Conferences 287 (2021): 02009. http://dx.doi.org/10.1051/e3sconf/202128702009.

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Synthesizing metal nanoclusters with diameters smaller than 5nm is challenging, but desirable because of the high ratio of surface area to interior atom. However, in this report it was achieved by utilizing magnesium-aluminium layered double hydroxide (Mg/Al-LDH) as a host for cobalt citrate anion precursor, which was later reduced into cobalt nanoclusters (Co-NC). Size of the Co-NC was controlled by changing the concentration of cobalt-citrate (Co-citrate) precursor during anion exchange. XRD and FTIR showed that Co-citrate precursor was successfully intercalated on the LDH while nitrogen adsorption/desorption isotherms confirmed that mesopores in the sample were formed after chemical reduction. Furthermore, TEM/STEM observations confirmed the formation of Co-NC. It was also verified that reducing the concentration of Co-citrate from 4mM to 0.5mM resulted in a reduction in the size of Co-NC from 4.4 to 1.3 nm. However, catalytic hydrogen generation from sodium borohydride (NaBH4) hydrolysis experiment indicated that catalytic activity decreased as the size of Co-NC decreases. This is mainly attributed to the limitation in mass transport within the interlamellar space of the smaller cluster LDH compared to the bigger one. Overall, Co-NC-LDH is a promising catalyst for NaBH4 hydrolysis. However, an optimum Co-NC size is critical for enhanced catalytic activity.

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30

Song, Wei, Ran Wang, Xiao Liu, Yongliang Guo, Ling Fu, and Chaozheng He. "Theoretical Study on V Atom Supported on N and P-Doped Defective Graphene for Electrocatalytic Nitrogen Reduction." Journal of The Electrochemical Society 168, no. 11 (November 1, 2021): 116516. http://dx.doi.org/10.1149/1945-7111/ac3a2e.

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Ammonia (NH3) is one of the most extensively produced chemicals worldwide, and it plays an important and indispensable role in the global economy. At present NH3 is mainly produced by the traditional Haber-Bosch process operated at high pressure and temperature, which results in massive energy consumption and carbon dioxide emissions. The electrochemical nitrogen reduction reaction (NRR) can allow the production of NH3 from nitrogen and water under ambient conditions and is regarded as a sustainable alternative to the Haber–Bosch process because of its low energy consumption and limited environmental impact. In this study, using density functional theory calculations, we designed a monovacancy defective graphene (MVG) doped with various nitrogen and phosphorus atoms and a single vanadium atom (VN1–3@MVG and VP1–3@MVG) to be used as electrocatalysts. The results revealed that N- and P-doping are beneficial for N2 adsorption and activation and can effectively reduce the energy barrier of the NRR, especially for P-doping. Among the synthesized electrocatalysts, double P-doped V@MVG demonstrated the best catalytic activity with a low free energy barrier of 0.43 eV. This paper reports the development of an efficient catalyst for electrochemical NH3 synthesis and provides valuable insights on the design of electrocatalysts with high activity and stability.

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31

Murniati, Murniati, Erin Ryantin Gunawan, Dedy Suhendra, Dina Asnawati, and Pujana Qurba. "Sintesis Senyawa-Senyawa Epoksi dari Asam Lemak Minyak Nyamplung (Calophyllum inophyllum L.)." Jurnal Riset Kimia 13, no. 1 (March 13, 2022): 89–99. http://dx.doi.org/10.25077/jrk.v13i1.447.

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Epoxidation is a reaction of a carbon double bond with active oxygen, which results in the addition of an oxygen atom, converting the original double bond into a three-membered epoxide (oxirane) ring. Generally, the raw material for making epoxy comes from petroleum. Nyamplung kernel oil is a non-edible oil that can be used as an alternative raw material for making epoxy derivatives. The purpose of this study was to determine the optimum conditions and characterization of epoxy materials. The fatty acids of Nyamplung kernel oil were reacted formic acid and hydrogen peroxide with sulfuric acid as a catalyst. The optimum condition of the following parameters on the study of this process was investigated: the epoxidation time, temperature, and the mole ratio of formic acid and hydrogen peroxide. The results showed that the optimum reaction conditions with the temperature was 65 oC, the mole ratio of formic acid and hydrogen peroxide was 1:6, and the reaction time was 75 minutes. The results of the characterization under optimum conditions showed the oxirane value of 1.69, the iodine number of 9.63 mg iod/100 g, and the epoxy conversion of 67.6 %. The results of FTIR characterization showed absorption at a wavenumber of 820.03 cm-1 which is a specific absorption from the oxirane ring of the epoxy compound.

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ROCHA, WILLIAN R., ÉDER S. XAVIER, JÚLIO C. S. DA SILVA, ROBERTA P. DIAS, HÉLIO F. DOS SANTOS, and WAGNER B. DE ALMEIDA. "AN EVALUATION OF QUANTUM CHEMICAL CALCULATIONS OF REACTION ENERGIES FOR CATALYTIC ACTIVATION PROCESSES: THE ACTIVATION OF PROPANE BY A RHODIUM CATALYST REVISITED." Journal of Theoretical and Computational Chemistry 11, no. 02 (April 2012): 297–312. http://dx.doi.org/10.1142/s0219633612500204.

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In this paper we report the state of the art CCSD(T)//MP2 ab initio calculations for the activation of propane by cyclopentadienyl carbonyl rhodium, (Cp)Rh(CO) , using the effective core potential of Hay and Wadt (LANL2DZ) for rhodium atom and the correlated consistent polarized valence double-ξ basis set (cc-pVDZ) for C , H and O atoms. The CCSD(T) energy values are used as reference to assess the effect of electron correlation on the reaction energies, as well as the performance of density functional theory (DFT) energy values using various functionals. An investigation on the accuracy of DFT results is relevant since their use in calculations involving large molecular systems is a computationally efficient strategy that enables us to tackle important problems in organometallics field and supramolecular chemistry. Our results for the small model system show that all DFT functionals used here correctly predict the CCSD(T) energy pattern and also reproduce very satisfactorily the MP2 geometrical parameters. The BP86, PBE1PBE and PW91 functionals exhibited the best agreement with structural parameters and relative energy values as compared with ab initio post-Hartree–Fock results, showing a potential use in theoretical investigations on larger systems.

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33

Chen, Wei, Binbin Wu, Yanyong Wang, Wang Zhou, Yingying Li, Tianyang Liu, Chao Xie, et al. "Deciphering the alternating synergy between interlayer Pt single-atom and NiFe layered double hydroxide for overall water splitting." Energy & Environmental Science 14, no. 12 (2021): 6428–40. http://dx.doi.org/10.1039/d1ee01395e.

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34

Gaidukevič, Justina, Rasa Pauliukaitė, Gediminas Niaura, Ieva Matulaitienė, Olga Opuchovič, Aneta Radzevič, Gvidas Astromskas, Virginijus Bukauskas, and Jurgis Barkauskas. "Synthesis of Reduced Graphene Oxide with Adjustable Microstructure Using Regioselective Reduction in the Melt of Boric Acid: Relationship Between Structural Properties and Electrochemical Performance." Nanomaterials 8, no. 11 (November 1, 2018): 889. http://dx.doi.org/10.3390/nano8110889.

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The melt of H3BO3 was used to reach a controllable reduced graphene oxide (rGO) synthesis protocol using a graphene oxide (GO) precursor. Thermogravimetric analysis and differential scanning calorimetry (TG/DSC) investigation and scanning electron microscopy (SEM) images have shown that different from GO powder, reduction of GO in the melt of H3BO3 leads to the formation of less disordered structure of basal graphene planes. Threefold coordinated boron atom acts as a scavenger of oxygen atoms during the process of GO reduction. Fourier-transform infrared (FTIR) spectra of synthesized products have shown that the complex of glycerol and H3BO3 acts as a regioselective catalyst in epoxide ring-opening reaction and suppress the formation of ketone C=O functional groups at vacancy sites. Thermal treatment at 800 °C leads to the increased concentration of point defects in the backbone structure of rGO. Synthesized materials were tested electrochemically. The electrochemical performance of these materials essentially differs depending on the preparation protocol. The highest charge/discharge rate and double-layer capacitance were found for a sample synthesized in the melt of H3BO3 in the presence of glycerol and treated at 800 °C. The effect of optimal porosity and high electrical conductivity on the electrochemical performance of prepared materials also were studied.

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35

Kumah, Robert Tettey, Sabathile Thandeka Mvelase, and Stephen Otieno Ojwach. "Syntheses and Applications of Symmetrical Dinuclear Half-Sandwich Ruthenium(II)–Dipicolinamide Complexes as Catalysts in the Transfer Hydrogenation of Ketones." Inorganics 10, no. 11 (October 29, 2022): 190. http://dx.doi.org/10.3390/inorganics10110190.

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The treatment of [Ru(η6-p-cymene)Cl2]2 with N,N’-(1,2-phenylene)dipicolinamide (H2L1) afforded the double salt complex [{Ru(η6-p-cymene)2-µ-Cl}L1][Ru(η6-p-cymene)Cl3], (Ru1) in moderate yields. Separately, the reactions of ligands (H2L1), N,N’-(4,5 dimethyl-1,2-phenylene)dipicolinamide (H2L2), and N,N’-(4-methoxy-1,2-phenylene)dipicolinamide (H2L3) with the [Ru(η6-p-cymene)Cl2]2 in the presence of KPF6 afforded the respective dinuclear half-sandwich Ru(II) complexes [{(Ru(η6-p-cymene)2--µ-Cl}L1][PF6] (Ru2), [{(Ru(η6-p-cymene)2-µ-Cl}L2][PF6] (Ru3), and [{(Ru(η6-p-cymene)2-µ-Cl}L3][PF6] (Ru4). NMR and FT-IR spectroscopies, ESI-MS spectrometry, and elemental analyses were used to establish the molecular structures of the new dinuclear ruthenium(II) complexes. Single crystal X-ray crystallography was used to confirm the piano-stool geometry of the dinuclear complexes Ru1 and Ru4, as containing N^N chelated ligand and bridging chlorido ligands in each Ru(II) atom. The complexes (Ru1-Ru4) showed good catalytic activities at low catalyst concentrations of 0.005 mol% in the transfer hydrogenation of a wide range of ketone substrates.

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36

Abdel-Mageed, Ali M., and Sebastian Wohlrab. "Review of CO2 Reduction on Supported Metals (Alloys) and Single-Atom Catalysts (SACs) for the Use of Green Hydrogen in Power-to-Gas Concepts." Catalysts 12, no. 1 (December 24, 2021): 16. http://dx.doi.org/10.3390/catal12010016.

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The valorization of carbon dioxide by diverting it into useful chemicals through reduction has recently attracted much interest due to the pertinent need to curb increasing global warming, which is mainly due to the huge increase of CO2 emissions from domestic and industrial activities. This approach would have a double benefit when using the green hydrogen generated from the electrolysis of water with renewable electricity (solar and wind energy). Strategies for the chemical storage of green hydrogen involve the reduction of carbon dioxide to value-added products such as methane, syngas, methanol, and their derivatives. The reduction of CO2 at ambient pressure to methane or carbon monoxide are rather facile processes that can be easily used to store renewable energy or generate an important starting material for chemical industry. While the methanation pathway can benefit from existing infrastructure of natural gas grids, the production of syngas could be also very essential to produce liquid fuels and olefins, which will also be in great demand in the future. In this review, we focus on the recent advances in the thermocatalytic reduction of CO2 at ambient pressure to basically methane and syngas on the surface of supported metal nanoparticles, single-atom catalyst (SACs), and supported bimetallic alloys. Basically, we will concentrate on activity, selectivity, stability during reaction, support effects, metal-support interactions (MSIs), and on some recent approaches to control and switch the CO2 reduction selectivity between methane and syngas. Finally, we will discuss challenges and requirements for the successful introduction of these processes in the cycle of renewable energies. All these aspects are discussed in the frame of sustainable use of renewable energies.

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37

Ma, Dongwei, Yuanyuan Wang, Liangliang Liu, and Yu Jia. "Electrocatalytic nitrogen reduction on the transition-metal dimer anchored N-doped graphene: performance prediction and synergetic effect." Physical Chemistry Chemical Physics 23, no. 6 (2021): 4018–29. http://dx.doi.org/10.1039/d0cp04843g.

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Present studies highlight the important role of the heteronuclear members for the development of the double-atom catalysts, and further provide a strategy to design efficient heteronuclear double-atom catalysts from the large chemical composition space for the electrocatalytic NRR.

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38

Chen, Hongyu, Ying Zhang, Qian He, Hao Zhang, Sheng Xu, Xiaohui He, and Hongbing Ji. "A facile route to fabricate double atom catalysts with controllable atomic spacing for the r-WGS reaction." Journal of Materials Chemistry A 8, no. 5 (2020): 2364–68. http://dx.doi.org/10.1039/c9ta13192b.

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Four double atom catalysts (DACs) with controllable interatomic distances were achieved via solventless ball-milling, among which double-atom Ni₂/N–C showed good selectivity and superior catalytic activity to single-atom Ni₁/N–C for r-WGS reactions.

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39

Yan, Yan, Haoyan Cheng, Zehua Qu, Rui Yu, Fan Liu, Qianwen Ma, Shuang Zhao, et al. "Recent progress on the synthesis and oxygen reduction applications of Fe-based single-atom and double-atom catalysts." Journal of Materials Chemistry A 9, no. 35 (2021): 19489–507. http://dx.doi.org/10.1039/d1ta02769g.

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40

Cao, Rong, Jie-Zhen Xia, and Qi Wu. "Computational Insight into Defective Boron Nitride Supported Double-Atom Catalysts for Electrochemical Nitrogen Reduction." Catalysts 12, no. 11 (November 10, 2022): 1404. http://dx.doi.org/10.3390/catal12111404.

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Designing highly selective and efficient double-atom electrocatalysts (DACs) is essential for achieving a superior nitrogen-reduction reaction (NRR) performance. Herein, we explored the defective boron nitride–supported cage-like double-atom catalysts to rummage the qualified NRR catalysts. Based on a systematic evaluation of the stability, N2 adsorption, NRR selectivity and activity of 10 DACs of TM1-TM2@VB-BN, we predicted Ru-Ti@VB-BN to be the NRR candidate with a limiting potential of −0.40 V. Compared to the corresponding single-atom catalysts, the introduction of Ti/Mo modulates the d-band center of the active metal atom, which improves the NRR performance. Moreover, the magnetic Ru-Ti dimer can facilitate the transfer of charge to molecular N2, ensuring a significant activation of the inert N≡N bond. This research not only opens up new avenues for designing boron nitride–supported DACs for NRR, but also deepens the understanding of DACs in N2 activation.

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41

Wang, Xiaoxia, Lin Lin, and Baihai Li. "First Principles Study of Double Boron Atoms Supported on Graphitic Carbon Nitride (g-C3N4) for Nitrogen Electroreduction." Crystals 12, no. 12 (December 2, 2022): 1744. http://dx.doi.org/10.3390/cryst12121744.

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Electrocatalytic reduction of N2 provides a clean, sustainable way for NH3 production. Efficient catalysts thus play a key role but remain a long-term challenge. In this study, the catalytic activity of double boron supported on graphitic carbon nitride (g-C3N4) for a N2 reduction reaction (NRR) is explored by density functional theory (DFT) calculations. Our results show that double boron atoms embedded in g-C3N4 with coordination of four N atoms and two boron atoms exhibits an excellent NRR performance with negligible energy consumption for adding hydrogen to *N2, while a moderate ΔG of 0.58 eV for the formation of the second NH3 suggests this catalyst is a potential candidate for N2 fixation.

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42

Xu, Yongkang, Zhewei Cai, Pan Du, Jiaxing Zhou, Yonghui Pan, Ping Wu, and Chenxin Cai. "Taming the challenges of activity and selectivity in the electrochemical nitrogen reduction reaction using graphdiyne-supported double-atom catalysts." Journal of Materials Chemistry A 9, no. 13 (2021): 8489–500. http://dx.doi.org/10.1039/d1ta00262g.

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43

Ying, Yiran, Xin Luo, Jinli Qiao, and Haitao Huang. "Double‐Atom Catalysts: “More is Different:” Synergistic Effect and Structural Engineering in Double‐Atom Catalysts (Adv. Funct. Mater. 3/2021)." Advanced Functional Materials 31, no. 3 (January 2021): 2170015. http://dx.doi.org/10.1002/adfm.202170015.

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44

Li, Tushuai, Yue Gu, Lisha Yu, Shenglong Zhu, Jie Zhang, and Yongquan Chen. "Stimuli-Responsive Double Single-Atom Catalysts for Parallel Catalytic Therapy." Pharmaceutics 15, no. 4 (April 11, 2023): 1217. http://dx.doi.org/10.3390/pharmaceutics15041217.

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Tumor microenvironment (TME)-induced nanocatalytic therapy is a trending strategy for tumor-targeting therapy, but the low catalytic efficiency remains to limit its therapeutic effect. The single-atom catalysts (SACs) appear as a novel type of nanozymes that possesses incredible catalytic activity. Here, we developed PEGylated manganese/iron-based SACs (Mn/Fe PSACs) by coordinating single-atom Mn/Fe to nitrogen atoms in hollow zeolitic imidazolate frameworks (ZIFs). Mn/Fe PSACs catalyze cellular hydrogen peroxide (H2O2) converting to hydroxyl radical (•OH) through a Fenton-like reaction; it also enhances the decomposition of H2O2 to O2 that continuously converts to cytotoxic superoxide ion (•O2−) via oxidase-like activity. Mn/Fe PSACs can reduce the depletion of reactive oxygen species (ROS) by consuming glutathione (GSH). Here, we demonstrated the Mn/Fe PSACs-mediated synergistic antitumor efficacy among in vitro and in vivo experiments. This study proposes new promising single-atom nanozymes with highly efficient biocatalytic sites and synergistic therapeutic effects, which will give birth to abundant inspirations in ROS-related biological applications in broad biomedical fields.

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45

Chen, Z. W., L. X. Chen, C. C. Yang, and Q. Jiang. "Atomic (single, double, and triple atoms) catalysis: frontiers, opportunities, and challenges." Journal of Materials Chemistry A 7, no. 8 (2019): 3492–515. http://dx.doi.org/10.1039/c8ta11416a.

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46

Rasool, Anjumun, Insha Anis, Mudit Dixit, Ashakiran Maibam, Afshana Hassan, Sailaja Krishnamurty, and Manzoor Ahmad Dar. "Tantalum based single, double, and triple atom catalysts supported on g-C₂N monolayer for effective nitrogen reduction reaction: a comparative DFT investigation." Catalysis Science & Technology 12, no. 1 (2022): 310–19. http://dx.doi.org/10.1039/d1cy01292d.

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Density functional theory simulations demonstrate that single and triple Ta-atom catalysts anchored to C2N monolayer act as superior catalysts for the nitrogen reduction reaction via alternating and distal pathways.

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47

Cheng, Jian, Jin Xie, and Chengjian Zhu. "Relay photocatalytic cascade reactions: synthesis of indolo[2,1-a]isoquinoline derivatives via double C(sp3)–H bond functionalization." Chemical Communications 54, no. 13 (2018): 1655–58. http://dx.doi.org/10.1039/c7cc09820k.

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A relay photoredox catalysis strategy concomitant with [1,5] hydrogen atom transfer has been applied in the construction of a biologically important indolo[2,1-a]isoquinoline framework via a cascade reaction. This reaction enables double C(sp³)–H bond functionalization and formation of two carbon–carbon double bonds.

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48

Chakrabarti, Kaushik, Bhaskar Paul, Milan Maji, Bivas Chandra Roy, Sujan Shee, and Sabuj Kundu. "Bifunctional Ru(ii) complex catalysed carbon–carbon bond formation: an eco-friendly hydrogen borrowing strategy." Organic & Biomolecular Chemistry 14, no. 46 (2016): 10988–97. http://dx.doi.org/10.1039/c6ob02010k.

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Bifunctional Ru(ii) complex (0.1 mol%) catalysed one-pot β-alkylation of secondary alcohols with primary alcohols and double alkylation of cyclopentanol were carried out successfully following the atom economical borrowing hydrogen methodology.

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49

Suggs, Kelvin L., Duminda K. Samarakoon, and Alfred Z. Msezane. "Drone Delivery of Dehydro-Sulfurization Utilizing Doubly-Charged Negative Ions of Nanoscale Catalysts Inspired by the Biomimicry of Bee Species’ Bio-Catalysis of Pollen Conversion to Organic Honey." Hydrogen 4, no. 1 (February 2, 2023): 133–45. http://dx.doi.org/10.3390/hydrogen4010009.

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The sulfur dioxide (SO2) compound is a primary environmental pollutant worldwide, whereas elemental sulfur (S) is a global commodity possessing a variety of industrial as well as commercial functions. The chemical relationship between poisonous SO2 and commercially viable elemental S has motivated this investigation using the Density Functional Theory calculation of the relative transition state barriers for the two-step dehydro-sulfurization oxidation–reduction reaction. Additionally, doubly-charged nanoscale platelet molybdenum disulfide (MoS2), armchair (6,6) carbon nanotube, 28-atom graphene nanoflake (GR-28), and fullerene C-60 are utilized as catalysts. The optimal heterogeneous and homogeneous catalysis pathways of the two-step oxidation–reduction from SO2 to elemental S are further inspired by the biomimicry of the honeybee species’ multi-step bio-catalysis of pollen conversion to organic honey. Potential applications include environmental depollution, the mining of elemental sulfur, and the functionalization of novel technologies such as the recently patented aerial and amphibious LynchpinTM drones.

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50

Li, Zheng, Jiasheng Li, and Jingya Yang. "Chemoselective Double Michael Addition: Synthesis of 2,6-Diarylspiro[Cyclohexane-1,3′-Indoline]-2′,4-Diones via Addition of Indolin-2-One to Divinyl Ketones." Journal of Chemical Research 41, no. 3 (March 2017): 168–71. http://dx.doi.org/10.3184/174751917x14878812592779.

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Seventeen examples of 2,6-diarylspiro[cyclohexane-1,3′-indoline]-2′4-diones were efficiently prepared by the Cs2CO3-catalysed chemoselective double Michael additions of indolin-2-one to divinyl ketones. This method has the advantage of high chemoselectivity, mild reaction conditions, high yield and atom- and step-economy.

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