Electropsun Ni-W/zeolite composite fibers for n-heptane hydrocracking and hydroisomerization

Nickel oxide-tungsten oxide/zeolite hydrocracking fibers were prepared by the electrospinning method and compared with the hydrocracking particles prepared by wet impregnation method. Scanning electron microscope, BET and XRD were used to characterize the two catalysts. The two catalysts were tested in a continuous flow fixed-bed reactor under 5 bars hydrogen pressure at 400 °C for n-heptane hydrocracking and hydroisomerization. The fibers registered a higher BET surface area compared to the particles as well as promising catalytic activity with C3 and iC4 formed as major cracking products; a higher conversion by 17 wt. % and 6 wt. % during the first 60 and 120 min on stream respectively compared to the hydrocracking particles. Apart from providing the hydrogenation function, the addition of the metallic component provided superior mechanical strength to the fibers when compared with the pure zeolite fibers. In addition, less coke was formed with the fibers. These novel composite fibers showed a uniform elemental distribution which is beneficial for a hydrocracking catalyst, providing close proximity of the acidic and hydrogenation sites. The latter which was reflected in less olefin formation and superior n-heptane isomerization. This study paves the way for promising research on utilizing zeolites in the form of fibers for various catalytic applications.