CeO2-promoted Cu2O-based catalyst sprayed on the gas diffusion layer for the electroreduction of carbon dioxide to ethylene

Abstract

The development of efficient and selective catalysts for the carbon dioxide reduction reaction (CO2RR) is crucial for sustainable energy and chemical synthesis. In this work, CeO2-y (y = C (cubic) and R (rod)) was incorporated into Cu2O nanocube electrocatalyst as a promoter for ethylene (C2H4) production. The results demonstrate that the catalyst with a loading of 5 wt% crystalline CeO2-C exhibits competitive activity and stability for ethylene production compared to pristine Cu2O. Under optimized reaction conditions of −250 mA cm−2 current density and 1 M KOH electrolyte, the Cu2O–5CeO2-C catalyst achieved a faradaic efficiency (FE) of ∼53% for C2H4 production, while maintaining stability over a period of 120 minutes. In contrast, non-promoted Cu2O exhibited a lower FE for C2H4 (∼38%) and experienced partial deactivation after 45 minutes. The characterization of the catalysts before and after the reaction revealed that the interaction between Cu2O and CeO2-C creates intrinsic sites (Cux–CeO2−x; Cux = Cu2+, Cu+, and Cu0) for the binding of CO2 and H2O molecules. Moreover, the Cu2O–5CeO2-C catalyst outperforms other reported systems in terms of FE and partial current density for C2H4 production. It requires a lower potential (−0.98 V vs. RHE) to operate at the same electrolyte concentration. This finding highlights the promising nature of Cu2O–5CeO2-C as an efficient and cost-effective catalyst for C2H4 production.