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/gcat∙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.
A small loading of highly dispersed Ru on Ni/MgAl2O4 catalyst was investigated in the dry reforming of methane (DRM) process. The catalysts were synthesized by impregnation and deposition-precipitation methods; the DRM reaction was performed at CH4/CO2/N2 = 1/1/1 and 600‒750°C. The bimetallic Ni‒Ru catalysts exhibited improved reducibility and metal dispersion compared with that of the Ni catalyst. Among the synthesized catalysts, the Ru(D)/Ni(I)/MgAl2O4 catalyst had the highest metal dispersion (7.23%) and largest amount of CO2 desorption (135 μmol/g). Thus, this catalyst exhibited the highest CH4 conversion (85.6%) at 750°C. Additionally, coke deposition of only 2.69% occurred during the stability test.