摘要
Electrochemical conversion of CO_(2)into valuable hydrocarbon fuel is one of the key steps in solving carbon emission and energy issue.Herein,we report a non-noble metal catalyst,nickel single-atom catalyst(SAC)of Ni_(1)/UiO-66-NH_(2),with high stability and selectivity for electrochemical reduction of CO_(2)to CH_(4).Based on ab initio molecular dynamics(AIMD)simulations,the CO_(2)molecule is at first reduced into CO_(2)-when stably adsorbed on a Ni single atom with the bidentate coordination mode.To evaluate its activity and selectivity for electrocatalytic reduction of CO_(2)to different products(HCOOH,CO,CH3OH,and CH_(4))on Ni_(1)/UiO-66-NH_(2),we have used density functional theory(DFT)to study different reaction pathways.The results show that CH_(4) is generated preferentially on Ni_(1)/UiO-66-NH_(2)and the calculated limiting potential is as low as-0.24 V.Moreover,the competitive hydrogen evolution reaction is unfavorable at the activation site of Ni_(1)/UiO-66-NH_(2)owing to the higher limiting potential of-0.56 V.Furthermore,the change of Ni single atom valence state plays an important role in promoting CO_(2)reduction to CH_(4).This work provides a theoretical foundation for further experimental studies and practical applications of metal-organic framework(UiO-66)-based SAC electrocatalysts with high activity and selectivity for the CO_(2)reduction reaction.
基金
This work was supported by the National Key Research and Development Project(Nos.2022YFA1503900 and 2022YFA1503000)
the National Natural Science Foundation of China(Nos.22033005 and 21963005)
the Natural Science Special Foundation of Guizhou University(No.202140)
the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)
The calculations were performed using supercomputers at the Center for Computational Science and Engineering of SUSTech and Shanghai Supercomputing Center.
