A viable system for carbon dioxide (CO₂) methanation over fibrous silica ZSM-5 for substitute natural gas (SNG)

Catalytic CO₂ methanation offers an attractive and sustainable way for the production of substituted natural gas (SNG), which may be used as a clean alternative energy source than fossil fuels. A metal-free fibrous silica ZSM-5 catalyst (FS@ZSM-5) was synthesized via the microemulsion technique to conduct catalytic CO₂ methanation. The FESEM, BET, and FTIR characterization techniques were used to investigate the surface morphology, pore structure of the catalysts. It was noticed that the commercialized ZSM-5 showed 37% CH₄ selectivity with a rate of methane formation 0.067 mmol m^-2s^-1. While FS@ZSM-5 exhibited high CH₄ selectivity of 66 % with rate of methane formation 0.108 mmol m^-2s^-1 using same conditions (T = 500 °C and GHSV = 36,000 mL h^-1 g^-1). Therefore, the FS@ZSM-5 was proved an efficient and active catalyst for CO₂ methanation activity.