Structure-Dependent Electrocatalytic CO2 Reduction Over Carbon-Supported CuSn Intermetallic Nano-Alloys

Abstract

The electrochemical reduction of CO₂ stands out as a groundbreaking approach to transform CO₂ into valuable fuels and chemicals, heralding the prospect of a carbon-neutral energy landscape and making strides in climate change mitigation. Among the various catalytic systems available, bimetallic alloys created through the intentional integration of metals showcase highly tunable active sites and remarkable catalytic performance. This research presents the innovative design of bimetallic CuSn alloys derived from metal-organic frameworks, leveraging their engineered surfaces and synergistic metal interactions to finely tune product selectivity. Cu drives alcohol formation, while Sn enhances formate production by stabilizing critical reaction intermediates and effectively suppressing the competing hydrogen evolution reaction. Notably, our Cu-rich CuSn/C-A catalyst achieves an impressive Faradaic efficiency of 71.1% for methanol, while the Sn-rich CuSn/C-B sets a near-record with 89.16% FE for formic acid in 0.1 M KHCO₃ at -0.7 V vs. RHE. These significant results highlight the critical role of alloy composition in directing CO₂ reduction selectivity, offering a powerful framework for the strategic design of high-performance, adaptable electrocatalysts.