Revealing the role of electrode potential micro-environments in single Mn atoms for carbon dioxide and oxygen electrolysis
Pengcheng Liu, Yanyi Liu, Kai‐Li Wang, Shuai Shi, Mengmeng Jin, Jingxiu Liu, Tao Qin, Qian Liu, Xijun Liu, Jia He
Abstract
Elucidation the relationship between electrode potentials and heterogeneous electrocatalytic reactions has attracted widespread attention. Herein we construct the well-defined Mn single-atom (MnSA) catalyst with four N-coordination through a simple thermal pyrolysis preparation method to investigate the electrode potential micro-environments effect on carbon dioxide reduction reactions (CO2RR) and oxygen reduction reactions (ORR). MnSA catalysts generate higher CO production Faradaic efficiency of exceeding 90% at −0.9 V for CO2RR and higher H2O2 yield from 0.1 to 0.6 V with excellent ORR activity. Density functional theory (DFT) calculations based on constant potential models were performed to study the mechanism of MnSA on CO2RR. The thermodynamic energy barrier of CO2RR is lowest at −0.9 V vs. reversible hydrogen electrode (RHE). Similar DFT calculations on the H2O2 yield of ORR showed that the H2O2 yield at 0.2 V was higher. This study provides a reasonable explanation for the role of electrode potential micro-environments.