International Journal of Hydrogen Energy, Vol.45, No.1, 640-649, 2020
Production of syngas via CO2 methane reforming process: Effect of cerium and calcium promoters on the performance of Ni-MSC catalysts
The dry reforming of methane (DRM) over Ni-MSC catalysts promoted by different Ce/Ca ratios was compared. The different Ce/Ca ratios proportions were introduced by coprecipitation. The catalysts with different content of promoter were characterized by N-2 adsorption, XRD, H-2-TPR and TEM. XRD and TEM results demonstrated that Ni-4Ce1Ca-MSC catalyst modified with high Ce/Ca had the best dispersibility and the smallest Ni particle size, resulting in more surface active sites. The synergy between Ce and Ca made a great contribution to prohibiting the generation of carbon deposits and the sintering of active metal during DRM procession. In contrast, catalysts modified only with Ca or Ce exhibited poor catalytic performance, resulting in significant deposition of carbon on the surface of the Ni-5Ca-MSC catalyst. In addition, the high Ce concentration greatly increases the oxygen storage capacity, which helps to form oxygen vacancies by mutual conversion of Ce4+/Ce3+ and Ni2+/Ni-0. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.