Synthesis and Experimental Screening of Catalysts for H2S to H2 Decomposition Under Close-to-Industry Conditions

The chemical engineering community has shown significant interest in investigating methods to decompose hydrogen sulfide into hydrogen and sulfur. However, there is still a lack of detailed experimental data enabling us to choose the optimal catalyst, reaction, and regeneration conditions, as well as the overall process design. The purpose of this work is to synthesize a series of catalysts and compare their catalytic activity under the same conditions, chosen on the basis of a possible large-scale H2S conversion process. To achieve this, the obtained catalysts were characterized by BET, XRD, SEM, TEM, and XPS before and after the reaction. Decomposition was conducted in a laboratory fixed-bed reactor at a temperature of 500 °C, 10 vol% of H2S in the feed, and a GHSV of 540–1000 h−1. DFT calculations evaluated the H2S bond cleavage on various catalyst surfaces. It was shown that the most promising catalyst was Ni3S2, offering an acceptable H2S conversion of 40%. We also observed that Ni3S2 catalyst regeneration could be conducted at much milder conditions compared to those previously reported in the literature. These results highlight the viability of upscaling the process with the selected catalyst.