Dynamic active sites on plasma engraved Ni hydroxide for enhanced electro-catalytic urea oxidation  

作　　者：Dan Li Yuefeng Zhang Xiaomin Zhou Chao Huang Ying Wen Liangliang Liu Qingwei Li Yue Xu Yuzheng Wu Qingdong Ruan Yinghe Ma Fangyu Xiong Dezhi Xiao Pei Liu Guomin Wang Babak Mehrjou Bin Wang Hao Li Rongsheng Chen Hongwei Ni Zhiyuan Zeng Paul K.Chu 

机构地区：[1]Department of Physics,Department of Materials Science and Engineering,and Department of Biomedical Engineering,City University of Hong Kong,Tat Chee Avenue,Kowloon 999077,Hong Kong,China [2]The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China [3]Catalysis Theory Center,Department of Physics,Technical University of Denmark,2800 Kongens Lyngby,Denmark

出　　处：《Journal of Energy Chemistry》2022年第8期150-158,I0005,共10页能源化学（英文版）

基　　金：the financial support from City University of Hong Kong Strategic Research Grant(SRG)(7005505);the National Natural Science Foundation of China(51601136 and 51604202)。

摘　　要：The urea oxidization reaction(UOR)is an important anodic reaction in electro-catalytic energy conversion.However,the sluggish reaction kinetics and complex catalyst transformation in electrocatalysis require activity improvement and better mechanistic understanding of the state-of-the-art Ni(OH)_(2) catalyst.Herein,by utilizing low-temperature argon(Ar)plasma processing,tooth-wheel Ni(OH)_(2) nanosheets self-supported on Ni foam(Ni(OH)_(2)-Ar)are demonstrated to have improved UOR activity compared to conventional Ni(OH)_(2).The theoretical assessment confirms that the edge has a smaller cation vacancy formation energy than the basal plane,consequently explaining the structural formation.Operando and quasi-operando methods are employed to investigate the dynamic evolution of the Ni(OH)_(2) film in UOR.The crucial dehydrogenation products of Ni(OH)_(5)O^(-)intermediates are identified to be stable on the etched edge and explain the enhanced UOR in the low potential region.In addition,the dynamic active sites are monitored to elucidate the reaction mechanism in different potential ranges.

关 键 词：Urea oxidization reaction Ni hydroxide Plasma processing DEHYDROGENATION Active site 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TQ426[化学工程]