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

A series of mesoporous Ni-Cu/WO3/ZrO2 (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/ZrO2 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 degrees 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 degrees C with a W surface density of 7.73 atom/nm(2) was mainly formed by WOx clusters, and WOx clusters with strong Bronsted acidity are catalytic active sites for skeletal rearrangement of hydroisomerization. The high activity of 1Ni1Cu/ mWZr-13 calcined at 750 degrees C is attributed to the proper surface acidity sites (696.34 mu mol.g(-1)) and Bronsted/Lewis ratio (0.35) of 1Ni1Cu/mWZr-13.