Constructing Mo2C/MoS2 heterojunction nanostructure as outstanding catalysts for CO2 hydrogenation

Abstract

The utilization of CO₂ to produce clean energy has become an inevitable trend in the global energy sector. Methanol, as an efficient energy storage chemical and a promising future alternative fuel, can be synthesized through the CO₂ hydrogenation with green hydrogen. In this work, Mo₂C/MoS₂-T catalysts with heterojunction nanostructures were synthesized using a surface carbonization strategy. The influence of carbonization temperature on the structural and morphological properties of the catalysts was systematically examined, with subsequent evaluation of their catalytic performance for synthesizing methanol from CO₂ hydrogenation. In situ diffuse reflectance infrared Fourier transform spectroscopy experiments revealed the coexistence of both formate route and CO route during CO₂ hydrogenation over the Mo₂C/MoS₂-T catalysts. Under the optimal reaction conditions, the Mo₂C/MoS₂-800 catalyst presented exceptional catalytic performance, achieving a 10.8 % conversion of CO₂ with a 95.4 % selectivity of methanol. Furthermore, the catalyst demonstrated exceptional long-term stability, maintaining consistent catalytic activity without noticeable deactivation during 150 h of continuous operation. This study establishes a straightforward yet effective strategy for the rational design of high-performance MoS₂-based catalysts, providing significant potential for industrial applications in CO₂ hydrogenation to methanol production.