Directly synthesized silver nanoparticles on gas diffusion layers by electrospray pyrolysis for electrochemical CO2 reduction

Abstract

Recently, the electrochemical CO2 reduction has been intensively researched for high selectivities and stabilities. The performance of electrochemical CO2 reduction can be restricted by mass transfer limitation from the low concentration of CO2(aq). Therefore, CO2 reduction systems with gas diffusion electrodes (GDE) have been suggested. CO2 reduction catalysts based on metals have been prepared primarily by a top-down approach from metal foil, which is not suitable for a gas diffusion reactor. In this study, nano-sized silver particles were deposited on a GDE of carbon paper by electrospray pyrolysis without additional immobilizing or annealing steps. The silver nanoparticles on carbon paper show the very high CO faradaic efficiency of 92%, the overpotential improved by similar to 200 mV, and the good stability for 10 h. The CO2 activity of the Ag particles is strongly depended on precursor types of silver (silver acetate) for the electrospray pyrolysis. Lastly, the GDE prepared by electrospray pyrolysis have been used for a twoelectrode gas diffusion flow cell for CO2 reduction. (c) 2019 Elsevier Ltd. All rights reserved.