Metal–Organic Framework-Templated Synthesis of Nickel–Alumina Nanocatalysts Improves Catalyst–Support Interaction for Higher Activity and Stability in Biogas Reforming under Controlled Oxidizing Conditions

Abstract

Tri-reforming methane with CO₂, O₂, and H₂O mixtures requires a delicate balance of dry-reforming, partial oxidation, and steam-reforming reactions to improve the CO₂ conversion and H₂/CO ratio. Nickel–alumina has been reported before for the tri-reforming of methane, although at higher temperatures (>900 °C). This is because the current approaches for nickel–alumina synthesis are ineffective in generating stronger catalyst–support interactions necessary to maintain higher active sites and stall carbon nanotube (CNT) deposition. Here, we report a synthesis method that allows controlled loading of nickel on alumina-based MIL-53 metal–organic framework followed by calcination to generate 2.5–10 wt % nickel nanoparticles dispersed on alumina. The 5 wt % nickel–alumina mixtures resulted in nanometer-sized crystallites, better metal dispersion, and more active sites for enhanced catalytic activity. This optimal loading of nickel allows stronger interaction with alumina for over 100 h of stable performance of tri-reforming at 800 °C, achieving ∼98% CH₄ conversion, ∼36% CO₂ conversion, and no carbon deposition while producing Fischer–Tropsch-ready feed containing a H₂/CO ratio of 3.2.