Cu-Based Materials for Enhanced C2+ Product Selectivity in Photo-/Electro-Catalytic CO2 Reduction: Challenges and Prospects

Abstract Carbon dioxide conversion into valuable products using photocatalysis and electrocatalysis is an effective approach to mitigate global environmental issues and the energy shortages. Among the materials utilized for catalytic reduction of CO 2 , Cu-based materials are highly advantageous owing to their widespread availability, cost-effectiveness, and environmental sustainability. Furthermore, Cu-based materials demonstrate interesting abilities in the adsorption and activation of carbon dioxide, allowing the formation of C 2+ compounds through C–C coupling process. Herein, the basic principles of photocatalytic CO 2 reduction reactions (PCO 2 RR) and electrocatalytic CO 2 reduction reaction (ECO 2 RR) and the pathways for the generation C 2+ products are introduced. This review categorizes Cu-based materials into different groups including Cu metal, Cu oxides, Cu alloys, and Cu SACs, Cu heterojunctions based on their catalytic applications. The relationship between the Cu surfaces and their efficiency in both PCO 2 RR and ECO 2 RR is emphasized. Through a review of recent studies on PCO 2 RR and ECO 2 RR using Cu-based catalysts, the focus is on understanding the underlying reasons for the enhanced selectivity toward C 2+ products. Finally, the opportunities and challenges associated with Cu-based materials in the CO 2 catalytic reduction applications are presented, along with research directions that can guide for the design of highly active and selective Cu-based materials for CO 2 reduction processes in the future.