Synthesis and hydrocracking performance of Y/ASA composite

In-situ covering technology was used to prepare the Y/ASA composite material in which Y zeolite was covered around with amorphous silica-alumina (ASA). Two kinds of supported Ni-W catalysts for hydrocracking of decane were prepared using Y/ASA and Y-ASA as supports, respectively. Y-ASA was a kind of mechanical mixture of industrial Y zeolite and ASA. The supports and catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy of pyridine adsorption and N₂ adsorption-desorption. The results showed that, while there were less total acid sites on Y/ASA and Ni-W/Y/ASA, there were more strong acid sites.The ratios of strong acid sites to weak acid sites of Y/ASA and Ni-W/Y/ASA were higher than those of Y-ASA and Ni-W/Y-ASA. The average pore diameter, mesopore surface area and pore volume of Y/ASA and Ni-W/Y/ASA were larger than those of the comparative samples, respectively. The hydrocracking of decane over the Ni-W/Y/ASA catalyst revealed that the conversion and yield of middle-component(C_5~9) were improved by 7.6 % and 12.4 %, respectively, compared with that over Ni-W/Y-ASA catalyst.