Hydrogen-Rich Gas Production by Steam Reforming and Oxidative Steam Reforming of Methanol over La0.6Sr0.4CoO3−δ: Effects of Preparation, Operation Conditions, and Redox Cycles

La_0.6Sr_0.4CoO_3-δ (LSC) perovskite, as a potential catalyst precursor for hydrogen (H₂)-rich production by steam reforming of methanol (SRM) and oxidative steam reforming of methanol (OSRM), was investigated. For this purpose, LSC was synthesized by the citrate sol-gel method and characterized by complementary analytical techniques. The catalytic activity was studied for the as-prepared and prereduced LSC and compared with the undoped LaCoO_3-δ (LCO) at several feed gas compositions. Furthermore, the degradation and regeneration of LSC under repeated redox cycles were studied. The results evidenced that the increase in the water/methanol ratio under SRM, and the O₂ addition under OSRM, increased the CO₂ formation and decreased both the H₂ selectivity and catalyst deactivation caused by carbon deposition. Methanol conversion of the prereduced LSC was significantly enhanced at a lower temperature than that of as-prepared LSC and undoped LCO. This was attributed to the performance of metallic cobalt nanoparticles highly dispersed under reducing atmospheres. The reoxidation program in repetitive redox cycles played a crucial role in the regeneration of catalysts, which could be regenerated to the initial perovskite structure under a specific thermal treatment, minimizing the degradation of the catalytic activity and surface.