(50b) Blue Hydrogen Production By Methane Cracking over Supported Metallic Catalysts: Effect of Metal Compositions and Supports

Blue hydrogen signifies an interim step towards cleaner energy production as well as low carbon economy. It is crucial for decarbonizing refineries, chemical and petrochemical industries, steel and cement manufacturing plants, and power generation. The present work reports blue hydrogen production via methane cracking over several mono- and bi-metallic catalysts on several supports. The catalysts include Ni, Ni-Ag, Ni-Ti, and Ni-W metals supported on Al-SBA-15, Al₂O₃, and date-biomass. All the catalysts have been prepared by the impregnation method, and the metal loading was fixed at 10 wt%. Different analytical techniques such as N₂-physisorption (BET surface area analysis), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Raman spectroscopy were applied to characterize surface area, pore size and pore volume, surface structure, morphology, and functionalities of the catalysts. The catalyst activity for methane cracking reaction was examined in a packed bed reactor at 450 ^oC and at atmospheric pressure. The synergy between the catalyst composition and their catalytic activity has been investigated for hydrogen production. The controlled synthesis has resulted in a series of catalysts with a high surface area (~300 m²/g). The catalysts with Al-SBA-15 support remained most active and stable due to the higher surface area, pore size, and thermal stability. Also, the SEM-EDAX analysis showed that the metals were very well dispersed on Al-SBA-15 support in comparison to Al₂O₃ and biomass-based supports, which could enhance the activity and durability. Both, Ni-Ti and Ni-W supported on Al-SBA-15 showed quite similar results in terms of activity (Methane conversion up to 83%) and stability (~ 35 h). The catalysts were found to be deactivated after ~90 h due to the deposition of solid carbon formed during methane decomposition reaction. The solid carbon was nanotubes with different lengths and diameters.