H2S Oxidative Decomposition Reaction in the Presence of CH4 over Metal-Sulfide-Based Catalysts: A Preliminary Investigation

Different alumina-supported metal sulfides catalysts were studied for the H2S oxidative decomposition reaction to simultaneously obtain sulfur and hydrogen in the presence of CH4. Mono and bimetallic catalysts were prepared, characterized, and tested at 1273 K by varying the contact time. X-ray diffraction and Raman evidenced a good dispersion of the Mo, Fe, and Co sulfide species on the Al2O3 support. From the experimental results, it was argued that Mo sulfide species are the active phases able to inhibit the formation of SO2, while the Fe sulfide species promote the selective abatement of COS and CS2 obtained because of the presence of CH4 in the gaseous feed stream. The bimetallic sample containing both Mo and Fe sulfide species (5Fe-10Mo/Al2O3) exhibited very interesting catalytic performances since it allowed us to achieve a H2 yield, CH4, and H2S conversion very close to the equilibrium values and the complete removal of sulfur compounds at low contact times.