Construction of Cobalt Porphyrin‐Modified Cu2O Nanowire Array as a Tandem Electrocatalyst for Enhanced CO2 Reduction to C2 Products

Abstract

AbstractHere, the molecule‐modified Cu‐based array is first constructed as the self‐supporting tandem catalyst for electrocatalytic CO2 reduction reaction (CO2RR) to C2 products. The modification of cuprous oxide nanowire array on copper mesh (Cu2O@CM) with cobalt(II) tetraphenylporphyrin (CoTPP) molecules is achieved via a simple liquid phase method. The systematical characterizations confirm that the formation of axial coordinated Co‐O‐Cu bond between Cu2O and CoTPP can significantly promote the dispersion of CoTPP molecules on Cu2O and the electrical properties of CoTPP‐Cu2O@CM heterojunction array. Consequently, as compared to Cu2O@CM array, the optimized CoTPP‐Cu2O@CM sample as electrocatalyst can realize the 2.08‐fold C2 Faraday efficiency (73.2% vs 35.2%) and the 2.54‐fold current density (‒52.9 vs ‒20.8 mA cm–2) at ‒1.1 V versus RHE in an H‐cell. The comprehensive performance is superior to most of the reported Cu‐based materials in the H‐cell. Further study reveals that the CoTPP adsorption on Cu2O can restrain the hydrogen evolution reaction, improve the coverage of *CO intermediate, and maintain the existence of Cu(I) at low potential.