Mo-based catalysts for CH4/H2S reforming to hydrogen production: effect of hydroxyl concentration of the support

High concentration of H2S in acidic natural gas will lead to poisoning of catalysts for hydrogen production by methane steam reforming, thus limiting the further use of natural gas. Reforming CH4 by H2S can be considered as an alternative route to hydrogen production from methane. This process not only achieves the removal of H2S but also obtains chemical raw material CS2 and clean energy H-2. By impregnating the Mo source on SiO2 treated with hydrogen peroxide and then using the catalyst in the CH4/H2S reforming reaction, we surprisingly found that the conversion rate of CH4 and H2S increased from 28 and 32% to 34% and 43%, respectively, after hydrogen peroxide treatment. The H-2 production rate and the yield of CS2 increased from 20 mmolH(2)/(g(Mo)*min) and 52% to 30 mmolH(2)/(g(Mo)*min) and 65%, respectively. Combining with characterization methods such as X-ray diffraction (XRD), hydrogen temperature programmed reduction (H-2-TPR), H-1-based solid-state nuclear magnetic resonance (H-1 MAS NMR), X-ray photoelectron spectroscopy (XPS), Raman spectra (RS), and transmission electron microscopy (TEM), we found that the hydroxyl concentration of the support increased after hydrogen peroxide treatment, which led to the strengthening of the force between the metal and the support, which was easy to form low-level and small-size MoS2, exposing more active sites, and further improving the catalytic activity. This method provides a new idea for hydrogen production by CH4/H2S reforming and the development of high-performance MoS2-based catalysts.