The influence mechanism of surface oxygen site regulation on CO2 hydrogenation to methanol catalyzed by MoS2/MoO2

The in-plane and edge sulfur vacancies (S v ) of MoS 2 serve as the active sites of CH 3 OH and CH 4 in CO 2 hydrogenation, respectively. However, edge sulfur vacancies are easily exposed, making it highly significant to inhibit their quantity and effectively promote methanol synthesis. In this study, we reported that MoS 2 /MoO 2 , obtained via calcination without metal doping or complex synthesis methods, undergoes structural rearrangement and active site regulation of MoS 2 . This modification not only significantly enhances the CO 2 conversion rate but also sharply reduces the sulfur vacancies at the edges of MoS 2 , enabling targeted control over CH 3 OH and CH 4 selectivity. Compared to pure MoS 2 , CO 2 conversion increased from 8.9 ​% to 13.5 ​%, while CH 3 OH selectivity rose dramatically from 2.5 ​% to 66.0 ​%. In-situ DRIFTS and DFT calculations demonstrate that CO 2 dissociates more readily at the edge oxygen vacancies of MoS 2 /MoO 2 , encountering a lower energy barrier, which accounts for the improved CO 2 conversion. The surface-bound CO∗ intermediates are formed and subsequently hydrogenated to species such as HCO∗. The formed CH 3 OH desorbs from the catalyst surface with lower energy, resulting in higher CH 3 OH selectivity. The catalyst exhibits excellent stability over 500 ​h and shows promising potential for industrial applications. This study provides theoretical insights and a novel research paradigm for designing highly active and selective Mo-based chalcogenide/oxide composites. It holds significant practical value for advancing the “double carbon” goal and facilitating energy structure transformation.