Recent progress in two-dimensional MXenes for the electrocatalytic reduction of CO2: a review.

The electrochemical CO2 reduction reaction has emerged as a promising strategy for converting carbon dioxide into value-added fuels and chemicals under mild conditions, offering a potential pathway toward carbon neutrality when coupled with renewable electricity. Among various catalyst candidates, MXenes have attracted increasing attention due to their high electrical conductivity, tunable surface terminations, large specific surface areas, and structural versatility. These characteristics make MXenes particularly attractive for regulating reaction intermediates and enhancing charge transfer during the CO2RR. This review systematically summarizes recent advances in MXene-based electrocatalysts for the CO2RR, with a focus on structure-activity-energy efficiency relationships. We first introduce the fundamental reaction mechanisms of the CO2RR. Subsequently, various synthesis strategies are critically reviewed in terms of their impact on surface terminations, stability, and scalability. Furthermore, modification strategies including heteroatom doping, defect engineering, and interface construction are critically discussed. Finally, current challenges and future opportunities for MXene-based CO2RR catalysts are outlined. This review aims to provide insights for the rational design of MXene-based electrocatalysts.