Design and synthesis of KIT-5/Beta composites under varied hydrothermal temperatures and evaluation of their hydrodenitrogenation performance

KIT-5/Beta composite supports were synthesized using an in situ self-assembly hydrothermal method, and NiW/KIT-5/Beta catalysts were prepared by impregnation. A series of characterization techniques were utilized to evaluate the influence of varying hydrothermal synthesis temperatures on the physicochemical properties of both the KIT-5/Beta supports and the resulting catalysts. The catalytic performances of catalysts were evaluated under reaction conditions of 320  °C, 4 MPa H2 pressure, and a weight hourly space velocity (WHSV) of 4.8 h−1 for hydrodenitrogenation (HDN) of quinoline. The results indicated that the specific surface area and pore structure of the materials could be effectively regulated by adjusting the hydrothermal synthesis temperature, which in turn influenced the number of active sites on the catalyst. The NiW/KB-125 catalyst, synthesized at 125  °C, presented the highest quinoline HDN efficiency (96.8%), which can be attributed to its favorable pore channel structure, greater Brønsted acid number, higher degree of metal sulfidation (80.12%) and appropriate metal-support interaction (MSI).