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

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.