Carbon dioxide reforming of methane on Ni–MgO–Al2O3 catalysts prepared by sol–gel method: Effects of Mg/Al ratios

Abstract

Carbon dioxide reforming of methane on Ni–MgO–Al2O3 catalysts has been investigated systematically at various Mg/Al ratios, focusing on catalytic activity and coke resistance. Ni catalysts supported on MgO–Al2O3 were prepared by sol–gel method using citric acid as a gelling agent. The characterization of the catalyst was carried out by XRD, TEM, TPR, N2 adsorption, H2 chemisorption, O2 titration, CO2-TPD and TGA. In the comparison with a catalyst prepared by coprecipitation method, it was found that the catalyst prepared by the sol–gel method showed higher coke resistance. In the variation of Mg/Al ratios, high coke resistance was obtained with increasing MgO loading, while high catalytic activity was observed with the catalysts of medium MgO/(MgO+Al2O3) ratio (0.44–0.86), of which the superior catalytic activity is likely attributed to high specific surface area and well dispersed Ni particles.