Directly imaging the in-situ chemical transformation of nickel cubane nanoclusters for promoting electrocatalytic urea-oxidation reaction  

作　　者：En-Xue Liu Hong-Hao Li Cheng Hou Jian-Qiang Zhao Mohamedally Kurmoo Yi-Jing Gao Zheng Yin Bin Zhang Ming-Hua Zeng 

机构地区：[1]State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources,School of Chemistry and Pharmaceutical Sciences,Guangxi Normal University,Guilin 541004,China [2]Hubei Collaborative Innovation Center for Advanced Chemical Materials,Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering,Hubei University,Wuhan 430062,China [3]Zhejiang Engineering Laboratory for Green Syntheses and Applications of Fluorine-Containing Specialty Chemicals,Institute of Advanced Fluorine-Containing Materials,Zhejiang Normal University,Jinhua 321004,China [4]Institute de Chimie de Strasbourg,CNRS-UMR7177,Universitéde Strasbourg,4 rue Blaise Pascal,Strasbourg 67070,France

出　　处：《Nano Research》2025年第2期218-226,共9页纳米研究(英文版)

基　　金：We acknowledge the grants from the BAGUI talent program in Guangxi Province(No.2019AC26001);the National Natural Science Foundation of China(Nos.22171075 and U23A2080).

摘　　要：We report the stepwise in-situ manipulation of a nickel cubane nanocluster capped with a specially designed multidentate ligand [Ni^(Ⅱ)_(4)(HL)_(3)(CH_(3)O)(CH_(3)OH)_(3)](CH_(3)COO)(Ni_(4),H_(3)L=(E)-3-((2-hydroxy-3-mehoxybenzylidene)amino)propane-1,2-diol) to firstly [Ni^(Ⅱ)_(4)(HL)_(3)(CH_(3)O)(CH_(3)OH)_(2)(H_(2)O)](CH_(3)COO)(Ni4-1min) and finally to [Ni^(Ⅱ)_(4)(HL)_(3)(CH_(3)O)(H_(2)O)_(3)](CH_(3)COO)Ni4-20h)during the urea electrolysis.A combination of mass spectrometry,single crystallography and pair distribution function were employed to analyze the structural correlations of this catalyst in crystal/solution/gas phases for confirming the dynamic ligand replacement while preserving the cubic Ni4 core during catalysis.The key feature of their structures is that:(i)three ligands wrap the Ni_(4)O_(4)cubane center on one side forming the rounded outside of a calix;(ii)the opposite flat side containing labile methanol as the active site.This structure facilitates the binding of the substrate to the active central nickel atoms during catalysis.Furthermore,due to the different modes of packing,the structure of Ni4-20 h sustains two-dimensional(2D)net of open space while the structures of Ni4 and Ni4-1 min have only closed void inaccessible to solvent molecules or ions.Interestingly,the overpotential initially decreased(up to 45 min)until it is stabilized.The result showed a low potential of 1.32 V(urea oxidation reaction(UOR))at 10 mA·cm^(-2)as reflected in the Gibbs free energy decrease of~0.4 eV from Ni4 to Ni4-20 h.This work demonstrates a convincing approach for elucidating the exact nature of the active clusters in electrocatalytic process,and confirms that in-situ modification of electrode materials might alter the direct electronic interaction between substrate and active sites in improving the catalytic performance.

关 键 词：atomically precise nanocluster nickel cubane electrode modification urea oxidation reaction 

分 类 号：O62[理学—有机化学]