CO2-reforming of methane to produce syngas over Co-Ni/SBA-15 catalyst: Effect of support modifiers (Mg, La and Sc) on catalytic stability. (October 2017) - Al-Fatesh, Ahmed Sadeq
Graphical abstract: Highlights: The promotional effect of La to Co-Ni/SBA-15 was insignificant. Mg and Sc considerably improved the metal species dispersion, MSI and Lewis basicity. Mg and Sc led to the significantly higher activity as well as stability. Sc emerged as a novel and excellent textural promoter to Co-Ni/SBA-15. Abstract: The catalytic performance of CO2 -reforming of methane over mesoporous Co-Ni/SBA-15-x (x = Mg, La and Sc) catalysts was investigated in 700–800 °C reaction temperature. The main target of this study was to obtain stable and active catalysts by the support modification with the addition of promoters. The catalysts were synthesized by hydrothermal method, whereas the characterization was carried out using XRD, BET, TPR, TPD, TGA/DTA and TEM. In case of Co-Ni/Mg-SBA-15 and Co-Ni/Sc-SBA-15, the better dispersion of Co and Ni species was obtained over the support due to the textural promoting effect of Mg and Sc, enhancing strong metal support interaction (MSI). Subsequently, the bimetals were successfully aligned and anchored into the hexagonal mesoporous channels of the supports. The dry reforming of methane was done in continuous fixed bed reactor under atmospheric pressure. Upon doping of Mg and Sc modifiers to the support, the CH4 conversion increased compared to the bare SBA-15 supported catalysts by 28% and 26%, while the CO2 conversion improved by 12% and 15%, respectively at 700 °C. TEM as well as TGA/DTA of the used catalysts revealed that the coke resistance was significantly improved as a result of the support modification, leading to the formation of amorphous carbon. Thus, the prolonged activity of Mg and Sc-modified support catalysts for 50 h revealed excellent stability of Co-Ni/SC-SBA-15 catalyst. Consequently, Sc emerged as a novel textural promoter, which remarkably improved the catalytic activity and exhibited outstanding stability.