Study of Nickel Catalysts Supported on MnOx–CeO2 Mixed Oxides in Dry Reforming of Methane
Maria V. Grabchenko, N. V. Dorofeeva, И. Н. Лапин, Valeria La Parola, Leonarda Francesca Liotta, O. V. Vodyankina
Abstract
Nickel-containing (10 wt % Ni) catalysts supported on CeO2–MnOх oxides with different Ce/Mn ratios (0.25, 1, and 9) have been synthesized and studied in dry reforming of methane (DRM). The low-temperature N2 sorption, XRD, and H2-TPR methods have been used to study the effect of the Ce/Mn ratio on the phase composition of the catalysts and the size and distribution of the Ni-containing oxide precursor to determine the role of MnOx phases and the Ce1 − xMnxO2 − δ solid solution in the formation of the active surface of the catalysts. The addition of manganese oxide contributes to the incorporation of Nin+ cations into the surface structure to form solid solutions, which leads to a decrease in the size of NiO crystallites on the support surface. The synthesized catalysts have been studied in the DRM process in the long-run temperature testing mode for 24 h. The catalyst based on a support with a Ce/Mn weight ratio of 0.25 has exhibited the highest activity and stability in DRM (X(CH4)/X(CO2) = 47/70); this fact has been attributed to the existence of a developed MnOx interface and the presence of fine Ni and MnNiOx particles on the surface.