Stabilizing Cu+ Species in Cu2O/CuO Catalyst via Carbon Intermediate Confinement for Selective CO2RR

Abstract

Copper oxide nanomaterials have been suggested to be efficient for highly selective multi-carbon (C2+) production in CO2 reduction reaction (CO2RR), due to the introduction of surface Cu+ species from oxide catalysts. However, the Cu+ species on the catalyst surface are prone to being reduced to Cu0 under reductive conditions during CO2RR. Here, a network-structured catalyst is developed consisting of ultrafine Cu2O/CuO nanoparticles that harbor an abundance of pores. This catalyst is synthesized via flame spray pyrolysis (FSP) method and engineered to confine carbon intermediates, which subsequently cover the local catalyst surface and stabilize Cu+ species. As a result, a C2+ products Faradaic efficiency (FE) of approximately 80.0% at a partial current density of 320.0 mA cm−2 is achieved, and a large C2+ to C1 ratio of ≈9.7. In situ XRD and XPS spectra are employed to reveal the indeed presence of Cu+ species on the catalyst surface during the CO2RR process, which extensively improves the adsorption of *CO intermediates and thus the C─C coupling reaction to form C2+ products.