Room-temperature methanol synthesis via CO₂ hydrogenation catalyzed by cooperative molybdenum centres in covalent triazine frameworks.

Abstract

Selective hydrogenation of CO₂ into methanol offers an ideal route for the utilization of greenhouse gas, but it remains a great challenge to be carried out under mild conditions due to the intrinsic chemical stability of CO₂. Here, we report sulfur-bridged cooperative molybdenum binuclear sites anchored on covalent triazine frameworks (denoted as Mo-S-Mo/CTF), as highly efficient active sites for CO₂ hydrogenation to methanol at room temperature. Under near-ambient conditions (30 °C, 0.9 MPa), Mo-S-Mo/CTF produces methanol with 96% selectivity and a methanol synthesis rate of 21.88 μmol g_MoSx^-1 h^-1. In-situ spectroscopic characterizations combined with theoretical calculations reveal that Mo-S-Mo/CTF favors CO₂ hydrogenation into methanol via the formate pathway at room temperature instead of the CO pathway at 150 °C. The cooperation of CO₂ activation on one molybdenum site and H₂ splitting on the other plays a key role in high catalytic activity. Our work provides a new direction for methanol synthesis at room temperature.