Highly efficient and stable methane dry reforming enabled by confinement-mass transfer balancing of Ni/DFNS catalysts

Abstract

Highly active and stable nickel-based catalysts are pivotal for the dry reforming of methane (DRM), yet achieving a balance between these two properties remains a significant challenge. This study reports a high-performance Ni/DFNS catalyst, fabricated by combining dendritic fibrous nanosilica (DFNS) with controlled fiber densities and Ni nanoparticles impregnated with ethylene glycol. It is found that both dense and sparse fiber densities decrease catalytic activity and stability. An optimal DFNS fiber density achieved a critical balance: it prevented the sintering of nickel particles via the spatial confinement effect derived from its unique fibrous morphology while simultaneously permitting rapid diffusion of reactants and products. Furthermore, ethylene glycol as a dispersant reduced the size of nickel particles and facilitated their uniform dispersion within the DFNS fiber channels. This synergistic effect not only exposed more nickel active sites to enhance catalytic activity but also strengthened the metal–support interaction to improve catalytic stability. Consequently, it exhibited excellent catalytic performance in terms of CO₂ conversion of 97.1%, demonstrating high thermal stability with only slight signs of deactivation. Overall, these findings inform the design of highly active, stable nickel-based catalysts that effectively suppress sintering and coking in DRM.