文献类型：期刊文献

英文题名：Recognition of surface oxygen intermediates on NiFe oxyhydroxide oxygen-evolving catalysts by homogeneous oxidation reactivity

作者：Hao, Yaming[1]; Li, Yefei[1]; Wu, Jianxiang[1]; Wang, Jinling[2]; Jia, Chenglin[1]; Liu, Tao[1]; Yang, Xuejing[2]; Liu, Zhipan[1]; Gong, Ming[1]

机构：[1] Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China; [2] National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai, 200237, China

年份：2020

外文期刊名：arXiv

收录：EI(收录号：20200638112)

语种：英文

外文关键词：Benzoic acid - Binary alloys - Electrocatalysts - Hydrogen production - Kinetic energy - Kinetics - Probes - Scaffolds

摘要：NiFe oxyhydroxide is one of the most promising oxygen evolution reaction (OER) catalysts for renewable hydrogen production, and deciphering the identity and reactivity of the oxygen intermediates on its surface is a key challenge but is critical to understanding the OER mechanism as well as designing water-splitting catalysts with higher efficiencies. Here, we screened and utilized in situ reactive probes that can selectively target specific oxygen intermediates with high rates to investigate the OER intermediates and pathway on NiFe oxyhydroxide. Most importantly, the oxygen atom transfer (OAT) probes (e.g. 4-(Diphenylphosphino) benzoic acid) could efficiently inhibit the OER kinetics by scavenging the OER intermediates, exhibiting lower OER currents, larger Tafel slopes and larger kinetic isotope effect values, while probes with other reactivities demonstrated much smaller effects. Combining the OAT reactivity with electrochemical kinetic and operando Raman spectroscopic techniques, we identified a resting Fe=O intermediate in the Ni-O scaffold and a rate-limiting O-O chemical coupling step between a Fe=O moiety and a vicinal bridging O. DFT calculation further revealed a longer Fe=O bond formed on the surface and a large kinetic energy barrier of the O-O chemical step, corroborating the experimental results. These results point to a new direction of liberating lattice O and expediting O-O coupling for optimizing NiFe-based OER electrocatalyst. Copyright ? 2020, The Authors. All rights reserved.