In Situ Carbon-Confined MoSe₂ Catalyst with Heterojunction for Highly Selective CO₂ Hydrogenation to Methanol

The synthesis of methanol from CO₂ hydrogenation is an effective measure to deal with global climate change and an important route for the chemical fixation of CO₂. In this work, carbon-confined MoSe₂ (MoSe₂@C) catalysts were prepared by in situ pyrolysis using glucose as a carbon source. The physico-chemical properties and catalytic performance of CO₂ hydrogenation to yield methanol were compared with MoSe₂ and MoSe₂/C. The results of the structure characterization showed MoSe₂ displayed few layers and a small particle size. Owing to the synergistic effect of the Mo₂C-MoSe₂ heterojunction and in situ carbon doping, MoSe₂@C with a suitable C/Mo mole ratio in the precursor showed excellent catalytic performance in the synthesis of methanol from CO₂ hydrogenation. Under the optimal catalyst MoSe₂@C-55, the selectivity of methanol reached 93.7% at a 9.7% conversion of CO₂ under optimized reaction conditions, and its catalytic performance was maintained without deactivation during a continuous reaction of 100 h. In situ diffuse infrared Fourier transform spectroscopy studies suggested that formate and CO were the key intermediates in CO₂ hydrogenation to methanol.