Dry reforming of methane over Ni catalysts supported on hierarchical ZSM-5 and USY zeolites

Abstract

In this study, 3 wt% of Ni supported on hierarchical ZSM-5 and USY zeolites were prepared using desilication and dealumination/desilication methods, respectively. These catalysts were used to produce syngas via dry reforming of methane. Mesoporosity was introduced in both zeolites, leading to increased initial values of CH₄ and CO₂ conversions, possibly attributable to higher Ni dispersion. The catalyst supported on hierarchical ZSM-5 exhibited a good NiO/Ni^2 + species distribution, an improved metal-support interface, and strong basicity. These aspects of the catalyst increased the number of accessible Ni active sites, resulting in higher stability, lower carbon formation, and reduced metal sintering. The inferior performance of the hierarchical USY-based catalyst could be ascribed to a greater quantity of trapped Ni²⁺ species within smaller pores, thus reducing their reducibility and hindering the accessibility of reagents to metal and basic sites.