(683c) Tri-Reforming of CH4 and CO2 to Syn-Gas over Nickel Catalyst Supported on Zirconia Derived Metal Organic Frameworks (MOFs) Catalyst

Tri-reforming of methane is a promising route for the utilization of greenhouse gases such as CH₄ and CO₂ to produce synthesis gas. The synthesis gas with the H₂/CO ratio of 1.5-2 is used as a feedstock in the Fischer-Tropsch process for the synthesis of various essential chemicals, including dimethyl ether (DME), higher alkenes, methanol, and substitute natural gas (SNG), etc., In this study, a very high surface area (670 m²/g) of Zr-MOF was synthesized via the solvothermal method and 5wt.% Ni/Zr-MOFs were synthesized by the impregnation technique. The catalyst was characterized by various methods, including N₂ adsorption-desorption, X-ray diffraction, FE-SEM, TGA, etc. Characterization results confirmed the formation of the Zr-MOF with both microporous and mesoporous structure. The tri-reforming activity of the catalyst was evaluated in a continuous downflow tubular packed bed reactor. The effect of the reaction temperature (600-800 ^oC) on the conversion of CO₂ and CH₄ and the synthesis gas composition was evaluated. Results dictated that pure Zr-MOF was not very active, which displayed low CH₄ (10.4%) and CO₂ (32.5%) conversion. However, at 800 ^oC in the presence of the optimum feed (CH₄: CO₂: H₂O: O_2: N₂) ratio (1: 0.5: 0.02: 0.1: 0.1), the obtained H₂/CO ratio was ~1.5. The catalyst activity was significantly improved after the incorporation of nickel metal into the Zr-MOF. In the presence of 5wt.%Ni/Zr-MOFs, the obtained CO₂ (28.5%) and CH₄ (80.2%) conversion was high at 700 ^oC. The higher activity was due to the presence of highly dispersed small-size (~) nickel particles on ZrO₂ derived from Zr-MOF. The nickel-metal helped to dissociate CH₄, and the basic microporous ZrO₂ enhanced the CO₂ conversion. At the optimum reaction condition, the catalytic activity and the H₂/CO ratio were almost constant (~1.6) for a longer period.