Tailored Ni-MgO Catalysts: Unveiling Temperature-Driven Synergy in CH₄-CO₂ Reforming

This study examines nickel catalysts on two different supports-magnesium oxide (MgO) and modified MgO (with 10 wt.% MOx; M = Ti, Zr, Al)-for their effectiveness in the dry reforming of methane. The reactions were conducted at 700 C-degrees in a tubular microreactor. The study compares the best-performing catalyst with a reference catalyst (5Ni/MgO) by conducting dry reforming of methane at different reaction temperatures. The catalysts are evaluated using surface area, porosity, X-ray diffraction, infrared spectroscopy, transmission electron microscope, thermogravimeter, and temperature-programmed techniques. The 5Ni/MgO + ZrO2 catalyst demonstrates inferior catalytic activity due to insufficient active sites. On the other hand, the 5Ni/MgO + TiO2 catalyst shows limited catalytic excellence due to excessive coke deposits, which are six times higher than other catalysts. The 5Ni/MgO and 5Ni/MgO + Al2O3 catalysts have the richest basic and acidic profiles, respectively. The 5Ni/MgO + Al2O3 catalyst is superior to other catalysts due to its stronger metal-support interaction on the expanded surface and the efficient diffusion of carbon on its less crystalline surface. At 700 C-degrees, this catalyst achieves 73% CH4 conversion, and at 800 C-degrees, it reaches 83% conversion. This study emphasizes the crucial role of the reaction temperature in reducing carbon deposition and enhancing the efficiency of the reforming process.