Metal and metal oxide electrocatalysts for the electrochemical reduction of CO 2 -to-C1 chemicals: are we there yet?

Electrochemical CO2 reduction reaction (CO2RR) into useful by products have received great and remarkable attention due to its promising route to mitigate the potential challenges regarding large CO2 emissions in the atmosphere. This technology will lead to recycle CO2 and achieve a carbon-neutral economy. This review summarizes the timeline of using metal and metal oxide catalysts and the latest developments CO2RR electrocatalysts, with a focus on systems producing C1 chemicals such as CO, HCOOH, CH4, and CH3OH. We first give a general introduction covering of the evolution of scientific production in the last two decades, the significance of this process, reaction mechanisms, catalyst evaluation criteria, and the broad spectrum of electrocatalysts. Some of the important contributions made to this field over the two past decades yielding the aforementioned C1 chemicals have then been reviewed. Finally, future directions and recommendations have been discussed to promote this technology to the industrial scale.