Sustainable syngas generation from methane: enhanced catalysis with metal-promoted nickel on silica–alumina composites

Abstract

To combat climate change and its association with emissions from fossil fuels, scientists are investigating sustainable substitutes. One promising approach is the dry reforming of methane, which turns greenhouse gases like CO₂ and CH₄ into lucrative syngas feedstock. However, catalyst optimization is necessary for effective dry reforming of methane. The optimum DRM conversion with perfect H₂ to CO ratio can only be achieved by stabilizing active sites “Ni” against high temperatures and increasing the interaction of CO₂ by using proper support and promoters. Investigating Ni catalysts on silica–alumina (SiAl) composites with promoters such as iridium (Ir), rhodium (Rh), ruthenium (Ru), platinum (Pt), and palladium (Pd) filled this research gap by modifying reducibility, basicity and crystallinity of the catalysts. The catalysts were analyzed by using different characterization approaches and optimized for the dry reforming of methane using a central composite design. The objectives were to determine the best promoter, optimize the procedure for maximum conversion rates and the optimal composition of syngas, and assess the catalytic characteristics. According to the results, Rh-promoted Ni catalysts performed the best, converting 93.1% of CO₂ and 87.0% of CH₄ under optimum circumstances, with an optimal H₂/CO ratio of 0.99 for syngas. The NiRh/SiAl outperforms others due to the extraordinary degree of reduction and higher side of reducibility of NiO which undergoes moderate interaction with the support.