A realistic take on MXenes for electrochemical reduction of carbon dioxide

Abstract

As part of concerted efforts in carbon capture and utilisation, electrochemical carbon dioxide reduction reaction (CO2RR) is a promising approach to realise a circular carbon economy. Two-dimensional metal carbides and nitrides (MXenes) have been touted as an attractive class of materials for CO2RR due to their tuneable electronic and surface properties, which provide a possible avenue to break linear scaling relations of intermediate binding energies that plague traditional transition metal catalysts. Despite the overwhelming number of theoretical studies with optimistic prospects for MXenes as CO2RR electrocatalysts, there remains a myriad of unresolved problems, alongside unexplored design opportunities, that require further experimental optimization to realise the promised potential of MXenes. Herein, we discuss how MXenes may break the above-mentioned scaling relations, as well as methods of MXenes modification that may improve their catalytic performance, including defect engineering and MXenes heterostructures. Lastly, we conclude by summarizing the current challenges and possible strategies to bring the potential of MXenes to fruition.