Influence of Supports on the Catalytic Activity and Coke Resistance of Ni Catalyst in Dry Reforming of Methane

The dependence of the catalytic activity and coke resistance of Ni-based catalysts on the support type was investigated in the dry reforming of methane (DRM). Catalysts were prepared using incipient wetness impregnation and analyzed using ICP-OES, BET-BJH, XRD, H₂-chemisorption, H₂-TPR, and CO₂-TPD. DRM was performed at 600–750^◦C at 144,000 mL/g_cat·h of GHSV (CH₄/CO₂/N₂ = 1/1/1). Ni/Al₂O₃ and Ni/MgO catalysts formed NiAl₂O₄ and NiO-MgO solid solutions, respectively, owing to strong binding between the metal and support. In contrast, MgO-Al₂O₃ and MgAl₂O₄ supports suppressed NiAl₂O₄ and NiO-MgO solid solution formation, due to Mg addition, with high metal dispersions of 4.6 and 6.6%, respectively. In the DRM reaction, the Ni/MgO-Al₂O₃ and Ni/MgAl₂O₄ catalysts showed high CH₄ conversions of 78.1 and 76.8%, respectively, compared with Ni/Al₂O₃ and Ni/MgO at 750^◦C. A stability test was performed at 600^◦C for 20 h. A coke study of the spent catalysts was performed using SEM and TGA. Alkaline-earth metal-containing catalysts Ni/MgO-Al₂O₃ and Ni/MgAl₂O₄ with strong CO₂ adsorption properties showed 20 wt% reduction in carbon deposition compared to commercial catalysts. Therefore, the support and basic properties of the catalyst significantly influenced the catalyst performance and coke resistance in the DRM.