摘要
Single atom catalysts(SACs) with isolated metal atoms dispersed on supports exhibit distinctive performances for electrocatalysis reactions.The designable realization of well-dispersed single metal atoms is still a great challenge owing to their ease of aggregation.Here,Mo single atomic sites(Mo-N_(3)C)combined with some ultrasmall Mo_(2)C/MoN clusters(Mo-SA/Mo_(2)C-MoN-Cs,mean diameter <2 nm) on nitrogen-doped porous carbon were synthesized via a simple pyrolysis of bimetallic Zn/Mo metalorganic frameworks.X-ray absorption near edge spectra(XANES) in combination with various characterizations show that most of Mo species in sample exist in the form of single sites and the exact structure is Mo-N_(3)C.Density functional theory(DFT) calculation further shows that as the number of Ncoordination in the Mo-NxC moieties increases,the positive cha rge of Mo atoms increases.The single Mo atoms in Mo-N_(3)C have the best capability of N_(2) adsorption,which may serve as main active sites for further electrochemical N2 reduction.
基金
the financial support from the Hunan Provincial Science and Technology Plan Project(Nos.2017TP1001,2020JJ4710)
the National Natural Science Foundation of China(No.21603109)
the Henan Joint Fund of the National Natural Science Foundation of China(No.U1404216)
the postdoctoral research funding plan in Central SouthUniversity(No.140050022)
the Fundamental Research Funds for the Central Universities(No.DUT20RC(3)021)
the 1W1B station for XAFS measurements in Beijing Synchrotron Radiation Facility(BSRF)。