High-loading Au nanoparticles on carbon by engineering surface charge and specific surface area of substrates

Energy transition towards net-zero society calls for utilization of renewable power to drive CO 2 conversion in an efficient electrochemical way. The development of a commercial CO 2 electrolyzer with positive tech-eco effect calls for active and durable electrocatalysts. High-loading gold on carbon (Au/C) with reduced particle size is the prerequisite for the highly-selective and highly energy-efficient CO production in such a CO 2 electrolyzer, but a scalable synthetic method is missing. With combined control of ligand, substrate and pH value, Au/C catalysts with particle size within 5 ​nm and metal loading of 40 ​wt% and 60 ​wt% are synthesized on low and high surface-area carbon, respectively. We also provide a thorough investigation of the effect of the ligand type, surface charge of gold nanoparticles (Au NPs) and surface area of carbon substrate on the loading limit of Au/C.