Engineering Cu-MXene to optimise hydrogen transport channel for accelerating methanol synthesis on ZnZrOx

Metal promotion is a common strategy to improve the hydrogenation activity of oxide catalysts. However, its efficacy is frequently hindered by insufficient hydrogen supply to active sites and the tendency of metal dopants to sinter under high-temperature conditions. Herein, we design a Cu-MXene/ZnZrO x composite catalyst, in which Ti vacancies within the MXene framework anchor Cu, enabling efficient hydrogen activation and subsequent spillover to ZnZrO x . In comparison with the conventional Cu/ZnZrO x catalyst, the Cu-MXene/ZnZrO x structure not only enhances the resistance of Cu species to high-temperature sintering but also significantly promotes the kinetics of hydrogen transfer. Additionally, this structural design facilitates the generation of a higher density of oxygen vacancies (OVs). As expected, the Cu-MXene/ZnZrO x catalyst demonstrates outstanding performance, achieving 12.3% CO 2 conversion and 91.2% methanol selectivity—exceeding all previously reported ZnZrO x -based systems. Density functional theory (DFT) calculations and Diffused reflectance infrared fourier transform spectroscopy (DRIFTS) indicate that atomically dispersed Cu sites facilitate H 2 dissociation, while the Cu-MXene interface promotes rapid H spillover to neighboring Zn-Zr sites, enhancing electron transfer and CO 2 reduction kinetics, thereby forming abundant active intermediates of HCOO* and CH 3 O*. This study offers a robust and scalable approach for developing highly efficient catalysts for CO 2 -to-methanol conversion.