Mesoporous Ni–Cu/WO_x/ZrO₂ Catalyst with Highly Dispersed WO_x Clusters: Efficient Catalysts for Selective Hydroisomerization of Isobutane to n-Butane

Abstract

A series of mesoporous Ni−Cu/WO 3 /ZrO 2 (1Ni1Cu/mWZr) was successfully prepared with F127 as a template and used as catalysts for isobutane hydroisomerization to n-butane. The effects of the F127/ZrO 2 molar ratio on the structure were investigated, and the results of characterization indicate that 1Ni1Cu/mWZr-13 has a high surface area (S BET = 86.96 m 2 •g −1 ). Using 1Ni1Cu/mWZr-13 calcined at 750 °C as a catalyst, the isobutane conversion and selectivity to n-butane were 80.74 and 62.66%, respectively, under optimal conditions. According to the characterization and catalytic activity results, the tungsten oxide of 1Ni1Cu/ mWZr-13 calcined at 750 °C with a W surface density of 7.73 atom/nm 2 was mainly formed by WO x clusters, and WO x clusters with strong Brønsted acidity are catalytic active sites for skeletal rearrangement of hydroisomerization. The high activity of 1Ni1Cu/ mWZr-13 calcined at 750 °C is attributed to the proper surface acidity sites (696.34 μmol•g −1 ) and Brønsted/Lewis ratio (0.35) of 1Ni1Cu/mWZr-13.