Аннотация:ABSTRACT
Hydrocracking of vacuum gas oil was studied over micro-mesoporous zeolite based catalysts, obtained by zeolite
Y recrystallization. The contribution of mesoporosity in recrystallized materials was varied by adjusting the
content of alkali and the temperature of hydrothermal treatment. The increase of recrystallization degree results
in the increase of mesopore to micropore volume of zeolite Y as well as to the decrease of the contribution of
strong Brønsted acid sites in faujasite cages and the increase of the contribution of Brønsted acid sites in mesopores.
The highest hydrocracking activity and middle distillates yield is achieved over NiMo catalyst obtained
with micro-mesoporous material with low degree of recrystallization. This effect is due to the improved accessibility
of active sites and easier transport of bulky molecules provided by mesopores, on the one hand, and
optimal zeolitic acidity, on the other hand. The highest selectivity to middle distillates is achieved over catalyst
with the highest degree of zeolite recrystallization. This observation can be explained by the decrease of the
contribution of strong BAS (bridging Si-O(H)-Al groups) accompanied by the increase of concentration of BAS in mesopores.