In Situ Carbon-Confined MoSe[sub.2] Catalyst with Heterojunction for Highly Selective CO[sub.2] Hydrogenation to Methanol

The synthesis of methanol from CO[sub.2] hydrogenation is an effective measure to deal with global climate change and an important route for the chemical fixation of CO[sub.2]. In this work, carbon-confined MoSe[sub.2] (MoSe[sub.2]@C) catalysts were prepared by in situ pyrolysis using glucose as a carbon source. The physico-chemical properties and catalytic performance of CO[sub.2] hydrogenation to yield methanol were compared with MoSe[sub.2] and MoSe[sub.2]/C. The results of the structure characterization showed MoSe[sub.2] displayed few layers and a small particle size. Owing to the synergistic effect of the Mo[sub.2]C-MoSe[sub.2] heterojunction and in situ carbon doping, MoSe[sub.2]@C with a suitable C/Mo mole ratio in the precursor showed excellent catalytic performance in the synthesis of methanol from CO[sub.2] hydrogenation. Under the optimal catalyst MoSe[sub.2]@C-55, the selectivity of methanol reached 93.7% at a 9.7% conversion of CO[sub.2] 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 CO[sub.2] hydrogenation to methanol.