High-Performance Electrocatalytic Reduction of Carbon Dioxide to Carbon Monoxide Using Biochar-Supported Gold Nanoparticles

The transformation of solid waste into high-value products is essential for advancing the circular economy. Developing a converted product with both high market potential and the ability to reduce carbon emissions is pivotal for next-generation sustainable catalysis. In this study, we advance waste-to-energy technology by developing a novel Au/biochar (Au/BC) composite electrocatalyst derived from swine manure, achieving both efficient CO2 electroreduction and effective solid waste valorization. Using swine manure biochar as a porous support for gold nanoparticles, we enhanced Au dispersion while minimizing noble metal consumption. The optimized Au/BC-1.2 catalyst achieves a high Faradaic efficiency of 87.72% for CO at −0.4 V vs RHE, with a CO partial current of 41.3 mA cm–2, while Au/BC-0.1 exhibits a notable mass activity of 9451 A·gAu–1. These findings offer a promising strategy for enhancing sustainable feed gas production in chemical engineering applications.