摘要
The electrochemical reduction of carbon dioxide(CO_(2)RR)is a promising strategy for achieving carbon neutralization.The Ni-N_(4) site is well known as the active site in metal single atoms on N-doped carbon catalysts,while its symmetric charge distribution nature is not favorable for electron transfer and then hindering the efficient CO_(2)RR.Herein,we constructed a Ni SA/CNs single-atom catalyst.Notably,it features unique Ni-N_(4)-O active sites,featuring one axial O atom and four planar N atoms,constituting a broken symmetrical electronic structure of Ni-N_(4) sites.Furthermore,hierarchical pore structures were obtained with the assistance of NaNO_(3) pore-forming agent during thermal treatment process,which promote electronic and mass transfer.And the resulting high specific surface area can host more Ni-N_(4)-O active sites.These specialized active sites promote the key intermediate(∗CO)adsorption/desorption and suppresses hydrogen evolution.Consequently,the Ni SA/CNs catalyst exhibits a high turnover frequency(TOF)value,reaching 34,081 h^(-1) at-0.98 V vs.RHE.Additionally,it achieves an excellent CO Faradaic efficiency,exceeding 90%,over a wide potential range from-0.4 V to-1.0 V vs.RHE.This work not only offers a new method for the rational synthesize single-atom catalysts with unique Ni-N_(4)-O active sites,but also provides in-depth insight into the origin of catalytic activity of porous carbon-base catalysts.
基金
financially supported by National High-Level Talent Fund
National Natural Science Foundation of China (Nos. 22372138,22461160253,22121001,and 22072118)
thank financial support from State Key Laboratory of Physical Chemistry of Solid Surfaces of Xiamen University
Shenzhen Science and Technology Program (No. JCYJ20220530143401002)
supported by Science and Technology Projects of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM) (No. HRTP-[2022]-3)
the Fundamental Research Funds for the Central Universities (No. 20720220008)
