Hidden Mechanism Behind the Roughness‐Enhanced Selectivity of Carbon Monoxide Electrocatalytic Reduction
Yinghuan Liu, Huijun Jiang, Zhonghuai Hou
Abstract
Abstract High roughness has been proved to be an effective design strategy for electrocatalyst in many systems. Especially, high selectivity of carbon monoxide reduction (CORR) in competition with the hydrogen evolution reaction has been observed on high roughness electrocatalysts. However, the two well‐known mechanisms, i.e., decreasing the energy barrier of CORR and increasing local pH, failed to understand the roughness‐enhanced selectivity in a recent experiment. Herein we unravel the hidden mechanism by establishing a comprehensive kinetic model for CORR on catalysts with different roughness factors. We conclude that the roughness‐enhanced CORR selectivity is actually kinetic controlled by local‐electric‐field‐directed mass transfer of adsorbed species on the electrode surface. Several ways to optimize CORR selectivity are predicted. Our work highlights the kinetics in electrocatalysis on nanocatalysts, and provides a conceptually new principle for future catalyst design.