Electrocatalytic carbon dioxide reduction:from fundamental principles to catalyst design

Electrocatalytic reduction of carbon dioxide (CO2) is one of the most promising technologies available to mitigate environmental problems introduced by the continuous increase in its concentration that has occurred since the industrial revolution. This technology also is attractive from the viewpoint that it can be based on carbon-neutral energy by converting CO2 into fuels and value-added chemicals using solar or other forms of renewable energy. In this review, fundamental concepts related to electrocatalysis, the electrical double layer, physical and chemical properties of CO2, the interaction of CO2 with electrode surfaces, and the sources of carbon and proton that underpin this technology are provided. Insights into recent mechanisms proposed for the electrocatalytic reduction of CO2 also are provided along with a survey of progress in the rational design of new electrocatalysts. Discussion on achievements in the field is focused on the variation in products formed by different electrocatalysts and the design strategies that have been introduced to alter the electronic and geometric properties of the electrocatalysts. Finally, recommendations for achieving further advances in electrocatalytic reduction of CO2 in a systematic manner are presented.