Electrocatalytic CO2reduction on nanostructured metal-based materials: challenges and constraints for a sustainable pathway to decarbonization

The increasing release of carbon dioxide into atmosphere has caused serious environmental consequences and closing the carbon loop is therefore essential for promoting the transition towards a sustainable development. Electrochemical reduction of carbon dioxide (E CO2RR) represents a powerful strategy for reducing CO2 levels in atmosphere and obtaining value-added chemicals and fuels using renewable energy sources. Despite the important achievements obtained so far, major issues associated with activity and selectivity of electrocatalysts toward the production of multi-carbon (C2+) products hinder large-scale applications. Hence, a thorough understanding of catalytic mechanisms is needed for advancing the design of efficient electrocatalysts to drive the reaction pathway to the desired products. This review summarizes the latest advances in the design of nanostructured metal-based catalysts for E CO2RR, with a special emphasis on the synthesis procedures and electrochemical performance of metal-nitrogen-carbon catalysts. An overview on the catalytic mechanisms is included along with a discussion of the experimental and computational techniques for mechanistic studies and catalyst development. Finally, we outline a perspective on the relationship between structure, morphology and electrochemical activity highlighting challenges and outlook on developing metal-nitrogen-carbon electrocatalysts for E CO2RR to multi-carbon products.