N-doped Ti3C2Tx MXene-regulated Metal-oxide Facilitates the Efficient Electrocatalytic CO2 Reduction to CO

CO₂ electroreduction reaction (CO₂ER) provides a promising pathway for scaling up the conversion of CO₂ to CO using renewable electricity, thereby providing an alternative potential pathway to carbon neutrality. Typically, the reaction conducted in aqueous media is an ideal way on the standpoint of sustainability. However, the undesired hydrogen evolution reaction (HER) is feasible to occur on catalyst surface together with CO₂ER, thereby reducing the overall CO₂-to-CO efficiency. In this work, we utilized the stacked structure of N-doped Ti₃C₂T_x MXene material supported metal oxide (ZnO) to form a ZnO/N-Ti₃C₂T_x catalyst in electrolytic CO₂ reduction to CO. The catalyst exhibited an Faradaic efficiency (FE_CO) of 96.4 % in CO₂ER at −0.967 V (vs. RHE) with a current density of 7.2 mA cm⁻². ZnO acted as the active site for CO₂ER in ZnO/N-Ti₃C₂T_x, while N-doped Ti₃C₂T_x MXene was responsible for enhancing textural properties and electrical conductivity, which could promote the mass transfer of gas molecules and electron transfer to ZnO active sites, and further improving the activity. This work inspires the rational design of unique metal oxide/N-Ti₃C₂T_x interfaces to regulate the high-performance electrocatalytic selectivity of CO₂ reduction.