Effects of MgO on Ni/Al2O3 catalysts for CO2 reforming of methane to syngas
Yousef Abdulrahman Albaqmaa, Ahmed S. Al‐Fatesh, Ahmed A. Ibrahim, Abdulaziz Bagabas, Fahad S. Al‐Mubaddel, Abdulaziz I. Alromaeh, Jehad K. Abu‐Dahrieh, Ahmed E. Abasaeed, Anis H. Fakeeha
Abstract
Abstract Carbon dioxide reforming of methane (CRM) converts CH 4 and CO 2 greenhouse gases into syngas over nickel-based catalysts. We performed CRM in a tubular microreactor at 700 °C by using 5.0 wt.% NiO catalyst, supported over mixtures of γ -Al 2 O 3 + x MgO ( x = 20, 30, 63, and 70 wt.%). The process of impregnation was used to prepare the catalysts. For characterization, N 2 -physisorption, XRD, H 2 -TPR, TGA, and Raman spectroscopy techniques were employed. Among the examined catalysts, 5Ni/Al 2 O 3 + 63%MgO was found the most active, where it showed ≅ 72% CH 4 conversion, 73% CO 2 conversion, and 0.82 H 2 /CO mole ratio over 7 h of reaction. The MgO modifier was the primary component, which favorably affected both Ni dispersion and stability, for the good interaction between NiO and γ -alumina. The mono-supported samples displayed the lowest total hydrogen consumption. In TGA, the 5Ni/Al 2 O 3 + 63%MgO exhibited a significant weight decrease (40%), reflecting its activity. Furthermore, the Raman spectroscopy analysis showed that the crystallinity of the carbon over this catalyst was more pronounced than the others.