Experimental and kinetic analysis of hydrogen production via hydrogen sulfide catalytic splitting

Hydrogen production via the decomposition of hydrogen sulfide is a promising process that enables the simultaneous abatement of a pollutant species, H2S, and the sustainable production of a high-value product, H2. Molybdenum disulfide has emerged as one of the most effective catalysts in enhancing this conversion. However, a detailed understanding of the reaction kinetics is still missing in the literature. In this work, the splitting of H₂S over MoS₂ was investigated in a tubular reactor at temperatures between 640 and 929 °C. A kinetic analysis was performed based on the newly collected data. A first model was developed using a power-law relation, which also accounted for the reverse reaction by introducing thermodynamic equilibrium constants. Additionally, a four-step reaction mechanism was proposed, and a rate equation was derived using the Langmuir-Hinshelwood approach. The kinetic parameters for both models were calculated and found to match the values reported in the literature. A comparison with the thermal decomposition of H₂S demonstrated the advantages of using MoS₂ as a catalyst, particularly at moderate temperatures. The findings of the study establish a solid basis for improving the efficiency of the process and, by providing reliable kinetics, facilitate its integration into industrial applications.