N-Bridged Ni and Mn Single-Atom Pair Sites: A Highly Efficient Electrocatalyst for Co2 Conversion to Co

Abstract

Herein, we report highly efficient diatomic electrocatalysts with Ni and Mn single-atom pair sites decorated on N-doped porous carbon framework for CO 2 conversion. The resulting catalysts can preferentially and rapidly convert CO 2 into CO with a high Faradaic efficiency of 98.3 % and an industrially relevant current density of - 300 mA cm -2  at a low overpotential of 0.287 mV in a GDE-based flow reactor cell. Furthermore, it exhibits high cathodic energetic efficiencies over 80 % for CO production even under industrially relevant current densities. The in-depth experimental measurements and theoretical calculations reveal that the synergistic electronic modification effect caused by coupling neighboring Ni and Mn single atoms exhibits favorable characteristics in reaction steps of CO 2 conversion such as CO 2 adsorption/activation and immobilization of CO 2 radical intermediate as well as adsorbed CO desorption, leading to highly efficient CO production.

Keywords: electrocatalysis, carbon dioxide conversion, diatomic site, nanomaterial, electronic tuning effect