Rare earth metals modified Ni–S2O82 −/ZrO2–Al2O3 catalysts for n-pentane isomerization

Abstract

The effects of adding rare earth (RE) metals, such as Ce, Yb and Pr to Ni–S2O82−/ZrO2–Al2O3 (Ni–SZA) on the structure of catalysts as well as their isomerization performance were studied. The prepared catalysts were characterized by XRD, BET, FT-IR, Py-IR, and H2-TPR. The results showed that the addition of RE metals can increase the strength and amounts of the acid sites, improve the redox properties of catalysts. The Yb–Ni-SZA catalyst showed the best redox properties, which could provide enough metallic sites. In addition, it provided the largest amounts of weak and moderately strong acid sites. Among RE metals modified Ni-SZA catalyst, Yb-Ni-SZA exhibited the highest isopentane yield of 61.7% at 160°C. The optimum isomerization catalytic performance of the catalysts decreased in the order of Yb-Ni-SZA>Pr-Ni-SZA>Ni-SZA>Ce-Ni-SZA.