Synthesis of methanethiol from CO2/H2S/H2 2 /H 2 S/H 2 catalyzed by hollow nanospheres VS4 4 with high catalytic activity

To optimize the utilization of the greenhouse gas CO2, 2 , high-performance catalysts should be designed and developed to promote the direct synthesis of methanethiol from CO2/H2S/H2. 2 /H 2 S/H 2 . Herein, we report a more efficient one-dimensional chain-structured VS4 4 catalyst. To investigate the impact of VS4 4 morphology, we compared its performance as a catalyst to the well-established two-dimensional layered structures, VS2 2 and MoS2. 2 . The results showed that VS4 4 with a nanometer hollow spherical structure exhibited excellent catalytic performance. The space-time yield of methanethiol was 206.12 mg & sdot;gcat & sdot; g cat- 1 & sdot;h- & sdot; h- 1 under the conditions of T = 320 degrees C, P = 1 MPa, GHSV = 16500 mL g- 1 h- 1 and V(CO2)/V(H2S)/V(H2) 2 )/V(H 2 S)/V(H 2 ) = 1/2/3. In addition, the CO2 2 conversion was 6.91% with the selectivity of CH4 4 at 2.4% and the selectivity of COS at only 24.23%, while the methanethiol selectivity reached 73.37%. Notably, no significant attenuation of the catalytic performance was observed after the reaction for 100 h, indicating that the catalyst has good industrialization application potential. The nano-hollow spherical structure provides surface area of 8.16 m 2 g-1 and a pore volume of 0.035 cm3 3 g-1,-1 , roughly double compared with micrometer sphere and micrometer rod structures. This morphology exposes more sulfur vacancy defects, thereby enhancing its adsorption activation capacity for CO2. 2 . In addition, its morphology facilitated the activation of H2 2 ang H2S 2 S molecules respectively, enhancing methanethiol selectivity. DRIFTS and DFT tests showed that the HCOO* species obtained by CO2 2 hydrogenation activation on nano-hollow spherical structure VS4 4 combined with the H2S 2 S species to generate the reaction intermediate COS, which was hydrogenated to produce methanethiol.