The role of adsorbed oleylamine on gold catalysts during synthesis for highly selective electrocatalytic reduction of CO2 to CO†
The low-coordinated sites of electrocatalysts favour hydrogen evolution, while the edge sites are active for CO2 reduction. Oleylamine is used to stabilize nanoparticles by adsorbing on the low-coordinated sites. The hydrogen evolution reaction was dramatically suppressed and the FECO remained >93% from −0.4 to −0.8 V (vs. RHE) when oleylamine ligands existed on the surface of a gold catalyst. More H+ and electrons were involved in the CO evolution reaction, which changed the rate-limiting step from single-electron transfer to the chemical reaction step. The results establish that the surface-adsorbed surfactants during catalyst synthesis have an important effect on CO2 electrocatalytic reduction.