Decomposition of H2S for hydrogen production by photothermal catalysis of Al2O3 loaded with different metals

Direct decomposition of H2S to produce H2 is currently one of the most promising H2S treatment technologies, but existing research methods are mostly in the stage of experimental study. Therefore, one of the main research directions in this field is to find a method with mild reaction conditions, low energy consumption, and high conversion rate. To this end, this paper explores a method of photothermal catalytic H2S decomposition for hydrogen production. Experiments are conducted on photothermal catalytic H2S decomposition for hydrogen production by loading different metals (Ni, Mo, Co) onto Al2O3, and the activity differences of Al2O3 loaded with different metals are compared. In addition, the catalysts are characterized and analyzed systematically by means of infrared imaging thermometry, X-ray diffraction, specific surface area, UV-visible diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy analysis methods and technologies. The following results are obtained. First, the loading of Ni, Mo, and Co significantly improves the catalytic activity of the catalyst, among which Mo/Al2O3 catalyst shows a relatively good activity, with H2S conversion rate up to 13.8% and H2 yield up to 208.5±6.5 µmol/(g·h) under the same light intensity (2.85 W/cm2). Second, the introduction of Mo enhances the photothermal effect of the catalyst, maximizing the surface temperature under the same light intensity. And it also reduces the accumulation of SO42- on the surface, exposing more active sites, so that molybdenum sulfide exhibits remarkable advantages in hydrogen production in the reaction. In conclusion, photothermal catalytic H2S decomposition for hydrogen production has a better catalytic activity than the traditional thermal catalytic H2S decomposition for hydrogen production. What's more, under the same condition, the H2S conversion rate and H2 yield of Al2O3 loaded with Mo increase by 1.6 times and 2.1 times, respectively. The research results can provide new ideas and technical references for H2S decomposition for hydrogen production. © 2025 Natural Gas Industry Journal Agency. All rights reserved.