Tri-reforming of methane over Ni/ZrO₂ catalyst derived from Zr-MOF for the production of synthesis gas

The increasing concentration of CO₂ and CH₄ in the environment is a global concern. Tri-reforming of methane (TRM) is a promising route for the conversion of these two greenhouse gases to more valuable synthesis gas with an H₂/CO ratio of 1.5–2. In this study, a series of Zr-MOF synthesized via the solvothermal method and impregnation technique was used to synthesize the nickel impregnated on MOF-derived ZrO₂ catalyst. The catalyst was characterized by various methods, including N₂-porosimetry, X-ray diffraction (XRD), temperature programmed reduction (TPR), CO₂-temperature programmed desorption (CO₂-TPD), thermo-gravimetric analysis (TGA), chemisorption, field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). Characterization results confirmed the formation of the Zr-MOF and nickel metal dispersed on MOF-derived ZrO₂. Further, the tri-reforming activity of the catalyst developed was evaluated in a downflow-packed bed reactor. The various catalysts were screened for TRM activity at different temperatures (600–850 °C). Results demonstrated that TRM was highly favorable over the NZ-1000 catalyst due to its desirable physicochemical properties, including nickel metal surface area (2.3 m²/g_cat⁻¹), metal dispersion (7.1%), and nickel metal reducibility (45%), respectively. Over the NZ-1000 catalyst, an optimum H₂/CO ratio of ~ 1.6–2 was achieved at 750 °C, and it was stable for a longer period of time.