Amorphous urchin-like copper@nanosilica hybrid for efficient CO2 electroreduction to C2+ products

Abstract

Currently most of research efforts for selective electrocatalysis CO2 reduction to C2+ products have relied on crystalline Cu-based catalysts; amorphous Cu with abundant low-coordinated atoms holds greater promise for this conversion yet remains relatively underexplored. Here we report an amorphous urchin-like Cu@nanosilica hybrid synthesized by electrostatic coupling Si polyanions with Cu salt in hydrothermal processes. The Cu@nanosilica electrocatalyst displays excellent CO2 electroreduction activity and selectivity with a Faradic efficiency of 70.5% for C2+ product production, and higher stability compared to the crystalline Cu counterpart. The solar-driven CO2 electrolysis yields an energy efficiency of 20% for C2+ product production. Mechanism study reveals that the urchin-like Cu@nanosilica catalyst with amorphous Cu/Cu+ dispersion enhances CO2 adsorption and activation to facilitate generation of CO2−* and possible CO* intermediates, and suppresses hydrogen evolution concurrently. The combined effects of both aspects promote efficient C2+ product production from CO2 electroreduction.