Effect of Ga-Promoted on Ni/Zr + Al₂O₃ Catalysts for Enhanced CO₂ Reforming and Process Optimization

In this study, zirconia-modified alumina support (S) was used to investigate Ga-promoted Ni catalysts for dry reforming of methane (DRM). The catalysts (Ni + (0–3) wt% Ga/S) were prepared using the wet impregnation method and calcined at 700 °C for 3 h. The inclusion of Ga enhanced the surface area, basicity, and metal-support interaction of the Ni-Ga/S catalysts. Smaller Ni particles containing Ga were seen in the TEM. The most active and stable catalyst was Ni + 2.0 Ga/S, having a conversion of 35% CO₂ and 28% CH₄ at 600 °C and displaying less (17%) carbon deposition. Furthermore, the DRM process was optimized by a mathematical model. The model determined the optimal conditions as follows: temperature (800 °C), gas flow rate (GHSV—30,000 ml h⁻¹gcat⁻¹), and methane to carbon dioxide ratio (1:1). The model predicts CH₄ and CO₂ conversions of 76.76% and 82.0%, respectively, and an H₂/CO ratio of 1.02, compared to experimental results showing CH₄ conversion at 74.56%, CO₂ conversion at 83.25%, and an H₂/CO ratio of 1.01. The model demonstrates excellent agreement with the experimental observations, exhibiting less than 3% error.