Effective production of biosyngas from biomethane over spatially confined Ni catalyst with captured CO₂

For the utilisation of biomethane and captured CO₂ , this work introduces a Ni/Al₂ O₃ egg-shell pellet catalyst synthesised via a developed wetness impregnation method that confines species to the pellet surface for efficient dry reforming of methane (DRM). High catalytic activity is achieved with only 0.5 wt% Ni. Calcination at 1200 °C reduces surface acidity, enhancing resistance to coking. The catalyst, C8-0.5Ni-T0.1-C12 (0.5 wt% Ni, 0.10 mm shell, calcined at 1200 °C), demonstrates the highest conversions (> 98 %) and strong resistance to coking (< 0.26 wt%). Electron microscopy reveals that metallic Ni particles coated with NiO shells suppress sintering and serve as essential active sites. Overall, the spatial distribution of Ni and high-temperature calcination govern performance and durability, establishing a practical catalytic design that connects biomethane valorisation, CO₂ utilisation, and biosyngas production, thereby advancing sustainable bioresource applications.