Design of original Silicon-based multielement electrocatalysts for CO2 reduction

The electrochemical CO2 reduction reaction (CO2RR) is a promising approach to producing sustainable fuels or chemical products from anthropogenic CO2 emissions. It can use electrical power generated by renewable sources to deliver valuable multi-carbon molecules (e.g., ethanol, propanol) and store energy in chemical bonds. Electrocatalysts needed to accelerate and make industrially viable this reaction suffer from poor selectivity among multi-carbon products. Our aim with SILICOR is to design a new family of nanocrystals with tunable chemical bonding to adjust the selectivity of CO2RR electrocatalysis. The target multielement nanocrystals will associate four chemical elements, specifically copper, prone to deliver multi-carbon products, another transition metal (e.g., nickel), and two p-block elements, silicon and phosphorus. These Cu-based silicophosphides will exhibit adjustable chemical bonding, from metallicity through ionicity to covalence, to adjust the electronic and geometric environment of copper catalytic sites and then adsorption of reaction intermediates, hence the selectivity. These original nanocrystals will be designed by the diffusion of Si and P atoms inside bimetallic Cu-based alloy nanoparticles. This novel approach of converting alloy nanoparticles will be enabled by an innovative liquid-phase synthesis approach where the nanoparticles will be dispersed into molten salts that will activate the diffusion processes. This work at the edge of nanosciences, electrocatalysis, and energy conversion will deliver new materials for the valorization of carbon dioxide emissions and hence accelerate the practical application of CO2 conversion technologies.