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911.
V. V. Yanilkin N. V. Nastapova V. I. Morozov V. P. Gubskaya F. G. Sibgatullina L. Sh. Berezhnaya I. A. Nuretdinov 《Russian Journal of Electrochemistry》2007,43(2):184-203
The electrochemical reduction of carbonyl-containing methanofullerenes is studied by methods of cyclic voltammetry and ESR with in situ electrolysis in the environment of 0.1 M Bu4NBF4 in o-dichlorobenzene-dimethylformamide (3:1 by volume). It is shown that the one-electron transfer onto the fullerene sphere of these compounds induces opening of the three-membered cycle, which leads to processes of retrocyclopropanation, transfer of the adduct onto the fullerene sphere of another molecule with the formation of bismethanofullerenes, and transformation into fullerodihydrofuran. The totality of competitive processes and the balance between these is defined by the nature of substituents at the exocarbon atom and the experimental conditions. The opening process is interpreted as the intramolecular electron transfer from the fullerene sphere onto the three-membered cycle. 相似文献
912.
分别利用固态反应和共沉淀法制备了铈锆固溶体,并以其为载体制备了车用三效催化剂,考察其在CH4和CO催化燃烧反应中的作用.研究发现固态反应法所得固溶体孔分布较宽,热稳定性较差,但表面较多的缺陷位贡献于其较高的储氧性能.而共沉淀法所得样品拥有较高的热稳定性和催化活性.固溶体的还原性质可以通过铈锆比调控.关联催化剂对CH4和CO的催化氧化性能发现,具有较大比表面积、集中孔径分布和较高储氧能力的固溶体显示了较低的催化剂起燃温度和较高的催化活性. 相似文献
913.
Photocatalytic CO2 reduction to C1 fuels is considered to be an important way for alleviating increasingly serious energy crisis and environmental pollution. Due to the environment-friendly, simple preparation, easy formation of highly-stable metal-nitrogen(M-Nx) coordination bonds, and suitable band structure, polymeric carbon nitride-based single-atom catalysts(C3N4-based SACs) are expected to become a potential for CO2 reduction under visible-light irradiation. In this review, we summarize the recent advancement on C3N4-based SACs for photocatalytic CO2 reduction to C1 products, including the reaction mechanism for photocatalytic CO2 reduction to C1 products, the structure and synthesis methods of C3N4-based SACs and their applications toward photocatalytic CO2 reduction reaction(CO2RR) for C1 production. The current challenges and future opportunities of C3N4-based SACs for photoreduction of CO2 are also discussed. 相似文献
914.
Bioelectrochemical dioxygen reduction reaction (ORR) catalyzed by multi-copper oxidases (MCOs) is a process of paramount importance occurring at the cathode of enzymatic biofuel cells (EBFCs), which is an energy harvester that holds promise of self-sustained implantable and wearable medical devices. The MCO biocathode is, however, frequently the limiting factor of a working EBFC. Besides the operational stability issue, enzymatic biocathodes are largely constrained by the relatively low solubility of dioxygen in aqueous solution. As an emerging topic, we here review the introduction of dioxygen-enriching materials to the cathodic bioelectrode for overcoming the dioxygen supply limitation, leading to improved ORR performance. 相似文献
915.
This review summarizes recent progress in understanding the oxygen reduction and evolution reactions at the lanthanum strontium manganite electrode of a high-temperature solid oxide cell. Information provided here is put into the perspective of the defect chemistry of lanthanum strontium manganite and its impact on the electrode reaction mechanisms itself. After summarizing recent views on the oxygen reduction reaction mechanism, the focus turns to the oxygen evolution reaction, which is significantly less treated in the literature. A combination of the information in the literature on both reactions was the basis for modified reaction mechanism of the oxygen evolution reaction to be proposed under consideration of recent experimental observations and theoretical findings. 相似文献
916.
Research progress of Pt and Pt-based cathode electrocatalysts for proton-exchange membrane fuel cells 下载免费PDF全文
Proton-exchange membrane fuel cells (PEMFCs) have been widely used commercially to solve the energy crisis and environmental pollution. The oxygen reduction reaction (ORR) at the cathode is the rate-determining step in PEMFCs. Platinum (Pt) catalysts are used to accelerate the ORR kinetics. Pt's scarcity, high cost, and instability in an acidic environment at high potentials seriously hinder the commercialization of PEMFCs. Therefore, studies should explore electrocatalysts with high catalytic activity, enhanced stability, and low-Pt loading. This review briefly introduces the research progress on Pt and Pt-based ORR electrocatalysts for PEMFCs, including anticorrosion catalyst supports, Pt, and Pt-based alloy electrocatalysts. Advanced preparation technology and material characterization of Pt-based ORR electrocatalysts are necessary to improve the performance and corresponding reaction mechanisms. 相似文献
917.
Xuan Liu Dr. Chengxi Huang Dr. Bo Ouyang Dr. Yongping Du Boyu Fu Zhengwei Du Qiang Ju Dr. Jingjing Ma Prof. Dr. Ang Li Prof. Dr. Erjun Kan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(43):e202201034
The CO2 reduction reaction (CRR) represents a promising route for the clean utilization of renewable resources. But mass-transfer limitations seriously hinder the forward step. Enhancing the surface hydrophobicity by using polymers has been proved to be one of the most efficient strategies. However, as macromolecular organics, polymers on the surface hinder the transfer of charge carriers from catalysts to reactants. Herein, we describe an in-situ surface fluorination strategy to enhance the surface hydrophobicity of TiO2 without a barrier layer of organics, thus facilitating the mass transfer of CO2 to catalysts and charge transfer. With less obstruction to charge transfer, a higher CO2, and lower H+ surface concentration, the photocatalytic CRR generation rate of methanol (CH3OH) is greatly enhanced to up to 247.15 μmol g−1 h−1. Furthermore, we investigated the overall defects; enhancing the surface hydrophobicity of catalysts provides a general and reliable method to improve the competitiveness of CRR. 相似文献
918.
Wenqing Wang Dr. Kun Rui Kaili Wu Yisha Wang Longwei Ke Xin Wang Feng Xu Prof. Yan Lu Prof. Jixin Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(40):e202200789
Realizing the synergy between active site regulation and rational structural engineering is essential in the electrocatalysis community but still challenging. Here, a matrix-confined co-pyrolysis strategy based on molecular bridging is demonstrated to realize highly dispersed Fe atoms on stereoassembled carbon framework. Both polyacrylonitrile matrix and organic linker from metal–organic frameworks (MOFs) provide sufficient N-anchoring sites for the generation of Fe−N4 moieties. A high Fe loading of 2.9 wt.% is readily achieved based on the scalable approach without post-treatment. Owing to the presence of highly exposed Fe−N−C sites and well-tuned pore structures, isolated Fe atoms on porous carbon nanofiber framework (Fe−SA/NCF) exhibits decent oxygen reduction activity and stability in alkaline conditions via a near four-electron path, demonstrating superior performance as air cathode for zinc-air batteries (ZABs) to commercial Pt/C catalyst. 相似文献
919.
Qianqian Fan Zirui Liu Feng Qiu Prof. Yong Mao Prof. Qingju Liu Prof. Longzhou Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(63):e202202700
The artificially accurate design of nonmetal electrocatalysts’ active site has been a huge challenge because no pure active species with the specific structure could be strictly controlled by traditional synthetic methods. Species with a multiconfiguration in the catalyst hinder identification of the active site and the subsequent comprehension of the reaction mechanism. We have developed a novel electro-assisted molecular assembly strategy to obtain a pure pentagon ring on perfect graphene avoiding other reconstructed structures. More importantly, the active atom was confirmed by the subtle passivation process as the topmost carbon atom. Recognition of the carbon-defect electrocatalysis reaction mechanism was first downsized to the single-atom scale from the experimental perspective. It is expected that this innovative electro-assisted molecular assembly strategy could be extensively applied in the active structure-controlled synthesis of nonmetal electrocatalysts and verification of the exact active atom. 相似文献
920.
The electrocatalysis of nitrate reduction reaction(NRR) has been considered to be a promising nitrate removal technology.Developing a highly effective iron-based electrocatalyst is an essential challenge for NRR.Herein,boron-iron nanochains(B-Fe NCs) as efficient NRR catalysts were prepared via a facile lowcost and scalable method.The Fe/B ratio of the B-Fe NCs-x can be elaborately adjusted to optimize the NRR catalytic performance.Due to the electron transfer from boron to metal,the metal-metal bonds are weakened and the electron density near the metal atom centers are rearranged,which are favor of the conversion from NO_3~-into N_2.Moreover,the well-crosslinked chain-like architectures benefit the mass/electron transport to boost the exposure of abundant catalytic active sites.Laboratory experiments demonstrated that the optimized B-Fe NCs catalyst exhibits superior intrinsic electrocatalytic NRR activity of high nitrate conversion(~80%),ultrahigh nitrogen selectivity(~99%) and excellent long-term reactivity in the mixed electrolyte system(0.02 mol/L NaCl and 0.02 mol/L Na_2 SO_4 mixed electrolyte),and the electrocatalytic activity of the material shows poor performance at low chloride ion concentration(Nitrate conversion of ~61 % and nitrogen selectivity of ~57% in 0.005 mol/L NaCl and 0.035 mol/L Na_2 SO_4 mixed electrolyte).This study provides a broad application prospect for further exploring the highefficiency and low-cost iron-based functional nanostructures for electrocatalytic nitrate reduction. 相似文献