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

Abstract Here, the molecule‐modified Cu‐based array is first constructed as the self‐supporting tandem catalyst for electrocatalytic CO 2 reduction reaction (CO 2 RR) to C 2 products. The modification of cuprous oxide nanowire array on copper mesh (Cu 2 O@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 Cu 2 O and CoTPP can significantly promote the dispersion of CoTPP molecules on Cu 2 O and the electrical properties of CoTPP‐Cu 2 O@CM heterojunction array. Consequently, as compared to Cu 2 O@CM array, the optimized CoTPP‐Cu 2 O@CM sample as electrocatalyst can realize the 2.08‐fold C 2 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 Cu 2 O can restrain the hydrogen evolution reaction, improve the coverage of * CO intermediate, and maintain the existence of Cu(I) at low potential.