Exploring the Reaction Mechanism of H₂S Decomposition with MS₃ (M = Mo, W) Clusters

Abstract

H 2 S is abundantly available in nature, and it is a common byproduct in industries. Molybdenum sulfides have been proved to be active in the catalytic decomposition of hydrogen sulfide (H 2 S) to produce hydrogen. In this study, density functional theory (DFT) calculations are carried out to explore the reaction mechanisms of H 2 S with MS 3 (M = Mo, W) clusters. The reaction mechanism of H 2 S with MoS 3 is roughly the same as that of the reaction with WS 3 , and the free-energy profile of the reaction with MoS 3 is slightly higher than that of the reaction with WS 3 . The overall driving forces (−ΔG) are positive, and the overall reaction barriers (ΔG b ) are rather small, indicating that such H 2 productions are product-favored. MS 3 (M = Mo, W) clusters have clawlike structures, which have electrophilic metal sites to receive the approaching H 2 S molecule. After several hydrogen-atom transfer (HAT) processes, the final MS 4 •H 2 (IM-4) complexes are formed, which could desorb H 2 at a relatively low temperature. The singlet product MS 4 clusters contain the singlet S 2 moiety, similar to the adsorbed singlet S 2 on the surface of sulfide catalysts. The theoretical results are compared with the experiments of heterogeneous catalytic decomposition of H 2 S by MoS 2 catalysts. Our work may provide some insights into the optimal design of the relevant catalysts.

Obtaining elemental sulfur for Martian sulfur concrete

“…In recent years, novel catalysts have been developed to facilitate this reaction. [76][77][78][79][80][81] The decomposition of H 2 S was also effected under ambient conditions using non-thermal plasma 82 or photocatalytic methods. 83,84 Alkali sulfides and alkaline earth sulfides are not viable sources for elemental sulfur, because they are stable enough to prevent their thermal decomposition.…”

“…In recent years, novel catalysts have been developed to facilitate this reaction. 76–81 The decomposition of H 2 S was also effected under ambient conditions using non-thermal plasma 82 or photocatalytic methods. 83,84…”

Progress and Perspectives for Solar‐Driven Water Electrolysis to Produce Green Hydrogen

“…Moreover, the energy storage device in PV-ES-EC system should possess high safety, high energy density, and good stability. [14][15][16] For instance, lithium-ion batteries and metal-air batteries have been reported to be charged by solar energy through a photovoltaic system, and then drive an electrolyzer as a stable power supply. As such, many issues in this field have remained to be solved notwithstanding the innovative efforts.…”

Dissociative Adsorption of H2S on Li(110) Surface Using Density Functional Theory Calculations and Car‐Parrinello Molecular Dynamics Simulations

“…The dissociative adsorption of H 2 S has been observed on the surfaces of various metals [21–24] . A systematic H 2 S dissociation study on Fe surface using first principles calculation reveals that the dissociation of H 2 S on Fe(110) surface is a thermodynamically as well as kinetically driven reaction, where the first S−H bond breaks with low energy barrier and the second S−H dissociation is barrierless [25] .…”

“…[10][11][12][13][14][15][16][17][18][19][20] The dissociative adsorption of H 2 S has been observed on the surfaces of various metals. [21][22][23][24] A systematic H 2 S dissociation study on Fe surface using first principles calculation reveals that the dissociation of H 2 S on Fe(110) surface is a thermodynamically as well as kinetically driven reaction, where the first SÀ H bond breaks with low energy barrier and the second SÀ H dissociation is barrierless. [25] A mechanistic study of H 2 S adsorption on Ni and Cu surface reveals Ni to be more active for H 2 S dissociation as compared to Cu surface.…”