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.

研究了通过Y型沸石重结晶制得的微孔沸石基催化剂对真空粗柴油进行加氢裂化。通过调节碱含量和水热处理温度，可以改变中孔在重结晶材料中的作用。重结晶度的增加导致沸石Y的介孔对微孔体积的增加，以及八面沸石笼中强布朗斯台德酸性位点的贡献减少，并且布朗斯泰德酸性位点在介孔中的贡献增加。与用重结晶度低的微介孔材料制得的NiMo催化剂相比，具有最高的加氢裂化活性和中间馏出物收率。这种效果是由于一方面改善了活性位点的可及性，另一方面又使中孔提供的大分子更易于运输，并且另一方面具有最佳的沸石酸度。相对于具有最高沸石重结晶度的催化剂，可以实现对中间馏出物的最高选择性。可以用强BAS（桥接Si-O（H）-Al基）的贡献减少，同时中孔中BAS浓度增加来解释这一现象。