Low-coordinated Co-Mn diatomic sites derived from metal-organic framework nanorods promote electrocatalytic CO2 reduction

The manipulation of the geometric coordination structure of diatomic site (DS) catalysts to promote the CO2-to-CO conversion process has garnered significant attention. However, the challenge remains in how to rationally design the catalytic microenvironment of DSs to enhance the kinetics of CO product formation. Herein, we present a post-synthetic co-substitution (PSCR) method for producing Co-Mn DS catalysts with low N coordination numbers (referred to as L-Co1Mn1-NC) on pre-designed N-doped carbon derived from metal-organic framework nanorods. When utilized in the process of CO2 electroreduction, the L-Co1Mn1-NC catalyst demonstrates a CO faradaic efficiency (FE) of up to 97.6% at -0.47 V, which is significantly higher compared to those of Co1Mn1-NC, Co-1-NC, and Mn-1-NC catalysts. In situ ATR-SEIRAS and theoretical simulations demonstrate that the creation of Co-Mn DSs with a lower N coordination number can notably facilitate the desorption of CO*, thus expediting the kinetics of the CO2-to-CO conversion process. This study introduces a novel approach to fine-tune the catalytic microenvironment of multi-atomic sites in order to facilitate the conversion and utilization of CO2.