A facile aqueous-phase synthesis method for small PdCu alloy nanocatalysts to enhance electrochemical CO2 reduction reactivity

Abstract

In a catalytic reaction involving nanoparticles, the particle size is an important factor influencing the reactivity. In this research, small PdCu alloy nanoparticles with an average size of 2.7 nm were easily synthesized by the co-reduction of Pd and Cu precursors using potassium bromide (KBr) as a capping agent to achieve size control in an aqueous phase. When the synthesized 2.7 nm-sized PdCu alloy nanoparticles were applied as an electrocatalyst for CO 2 reduction reaction (CO 2 RR), using a gas diffusion electrode system, Faradaic efficiency (FE) of over 80% for CO with a significantly low H 2 selectivity (≤2% FE) at 100 mA/cm 2 was achieved. The results revealed that the synthesized nanoparticles are highly suitable for CO 2 -to-CO conversion at high current densities. • A mild condition synthetic route to highly crystalline PdCu alloy. • The particle size of the PdCu is easily controlled by adjusting the amount of Kbr. • 2.7 nm-sized PdCu alloy showed enhanced FE for CO and the lowest FE for H 2 production at relatively high current density of 100 mA/cm 2 compared to 3.5 nm PdCu.