Highly dispersed, single-site copper catalysts for the electroreduction of CO2 to methane

Pyrolyzing Cu(II) precursors absorbed on carbon black gave an eletrocatalytic material for the electroreduction of CO2. Controlled potential electrolysis and GC analysis revealed an unexpected selectivity towards methane even in alkaline media, with a methane Faradaic efficiency as high as 42%, a partial current density of 100 mA/cm2 (at −1 V vs. RHE) and a methane/ethylene ratio of 4:1. XPS, EXAFS, and EDX mapping results indicate a single-site Cu(I) center as the catalytically active site. The limited size of the active sites is believed to be crucial for the preferential formation of methane over ethylene. [Display omitted]