Selective Electrochemical CO2-to-Syngas Conversion Enabled by Electronic-Structure-Modulated Copper-Zinc Alloy Nanosheets

Abstract

Developing cost-effective materials for efficient selective electrochemical CO₂-to-syngas under actionable conditions is a practical and promising way to sustain low-carbon energy supplies, which remains a significant challenge. Herein, the efficient CuZn alloy nanosheets with prominent electronic structure modulation and alloy effect and the active CuZn₅ phase are successfully fabricated by the facile electrodeposition strategy are reported. The electronic synergy via electron transferring from Zn to Cu can influence the catalyst's surface electron density and thus regulate the chemical adsorption properties of both small molecules and the key step of C═O bond cleavage. Significantly, the engineered Cu_0.07 Zn alloy catalyst achieves an outstanding electrochemical CO₂-to-syngas conversion, accompanying Faraday efficiency of near 100% and a high production rate of syngas with tunable CO/H₂ ratio of 1.1 to 4.3 over a wide potential range of −0.65 to −1.25 V as well as excellent stability in CO₂-saturated 0.1 m KHCO₃ system. Moreover, the comprehensive understanding of the alloy phase evolution, electronic structure modulation, structure-activity relationship, and possible CO₂-to-syngas conversion mechanism involving the rate-determining step of C═O bond breakage to ^*CO species over the versatile CuZn alloy catalyst via theoretical calculations and in situ spectroscopy is demonstrated.