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 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, this catalyst achieves 73% CH₄ conversion, and at 800 °C, 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.