Electrocatalysis for CO2conversion: from fundamentals to value-added products

The continuously increasing CO₂ released from human activities poses a great threat to human survival by fluctuating global climate and disturbing carbon balance among the four reservoirs of the biosphere, earth, air, and water. Converting CO₂ to value-added feedstocks via electrocatalysis of the CO₂ reduction reaction (CO₂RR) has been regarded as one of the most attractive routes to re-balance the carbon cycle, thanks to its multiple advantages of mild operating conditions, easy handling, tunable products and the potential of synergy with the rapidly increasing renewable energy (i.e., solar, wind). Instead of focusing on a special topic of electrocatalysts for the CO₂RR that have been extensively reviewed elsewhere, we herein present a rather comprehensive review of the recent research progress, in the view of associated value-added products upon selective electrocatalytic CO₂ conversion. We initially provide an overview of the history and the fundamental science regarding the electrocatalytic CO₂RR, with a special introduction to the design, preparation, and performance evaluation of electrocatalysts, the factors influencing the CO₂RR, and the associated theoretical calculations. Emphasis will then be given to the emerging trends of selective electrocatalytic conversion of CO₂ into a variety of value-added products. The structure-performance relationship and mechanism will also be discussed and investigated. The outlooks for CO₂ electrocatalysis, including the challenges and opportunities in the development of new electrocatalysts, electrolyzers, the recently rising operando fundamental studies, and the feasibility of industrial applications are finally summarized.