Optimizing reaction paths for methanol synthesis from CO 2 hydrogenation via metal-ligand cooperativity

Abstract

As diversified reaction paths exist over practical catalysts towards CO 2 hydrogenation, it is highly desiderated to precisely control the reaction path for developing efficient catalysts. Herein, we report that the ensemble of Pt single atoms coordinated with oxygen atoms in MIL-101 (Pt 1 @MIL) induces distinct reaction path to improve selective hydrogenation of CO 2 into methanol. Pt 1 @MIL achieves the turnover frequency number of 117 h −1 in DMF under 32 bar at 150 °C, which is 5.6 times that of Pt n @MIL. Moreover, the selectivity for methanol is 90.3% over Pt 1 @MIL, much higher than that (13.3%) over Pt n @MIL with CO as the major product. According to mechanistic studies, CO 2 is hydrogenated into HCOO* as the intermediate for Pt 1 @MIL, whereas COOH* serves as the intermediate for Pt n @MIL. The unique reaction path over Pt 1 @MIL not only lowers the activation energy for the enhanced catalytic activity, but also contributes to the high selectivity for methanol.