Synthesis of Cu-based nanoparticulated electrocatalysts for CO2 electroreduction by supercritical fluid deposition

Abstract

This work has focused on the synthesis of Cu nanostructured electrocatalysts for CO2 electroreduction by supercritical fluid deposition (SFD) technique. Different synthesis strategies such as the suppression of cosolvent (methanol) and/or reducing agent (hydrogen) have been studied. Good copper deposition yields (around 85%) have been attained in the absence of hydrogen. This material (C-200Me) has been tested as catalyst in the electrochemical reduction of CO2 in gas phase and the results obtained have been compared with those achieved with a catalyst synthesised using H2 as reducing agent (C-200H2Me). CO and formic acid have been the main reduction products with both catalysts. CO2 conversion rate has been almost six times higher with C-200H2Me, what may be probably attributed to a higher proportion of Cu0/Cu+ species in this catalyst. These results indicate the higher catalytic activity of Cu0 (than that of Cu2O) in the electrocatalytic reduction of CO2 in gas phase.