Increasing Oxygen Vacancies by Incorporating Co into Nano ZnO for Selective Hydrogenation of CO₂ into Methanol

CO 2 to methanol is considered a promising method for CO 2 conversion and utilization, yet achieving desirable selectivity remains a significant challenge. Herein, efficient CO 2 hydrogenation to methanol is achieved by synthesizing Co 0.7 ZnO with abundant oxygen vacancies (O v ) through the incorporation of a portion of Co into nanoscale ZnO. By tuning the molar ratio of Co/(Co+Zn) in Co x ZnO to increase the O v content to 71%, CO 2 adsorption and activation to form formate (COOH*) are enhanced, thereby reducing the CO selectivity. The efficiency of the hydrogenation of CO 2 to methanol was optimized with Co 0.7 ZnO, which exhibited an impressive methanol formation rate of 2.1 mmol/(g h) and a selectivity of up to 96.7%. The unique structure of incorporating partial Co into nanoscale ZnO to increase the level of O v not only reduces the level of CO selectivity but also inhibits methane formation, thereby contributing to the high methanol selectivity. This study presents an innovative strategic design through partial doping, which is essential for controlling the selectivity of target products in the CO 2 hydrogenation.