多级孔分子筛在重油加氢裂化催化剂的应用进展

分子筛是加氢裂化催化剂关键组分，其性质影响着加氢裂化反应效率和产品分布。微孔分子筛的孔结构降低了大分子反应物的扩散效率和酸中心的可及性，不宜直接用作加氢裂化催化剂的载体。本文从分子筛的孔结构和酸中心可及性的角度出发，介绍了具有多级孔体系的分子筛和具有核壳结构分子筛的加氢裂化性能。与相应的参比剂比较，分子筛的多级孔结构能大幅提高反应物种的扩散效率和酸中心的可及性，呈现出更好的催化活性、稳定性以及目标产物选择性。此外，金属加氢活性中心与分子筛裂化活性中心的合理调配，也是多级孔分子筛在重油加氢裂化应用中面临的挑战。

Development of hierarchical zeolites in hydrocracking catalysts of heavy oil

Zeolite is the key component of hydrocracking catalyst, and its properties affect the hydrocracking reaction efficiency and product distribution. The microporous structure of zeolite reduces the diffusion efficiency of macromolecular reactants and the accessibility of acid sites, hence, it is not suitable to be used as the carrier of hydrocracking catalyst directly. In this paper, the properties of zeolites with hierarchical pore structure and zeolites with core-shell structure are introduced from the view of pore structure and acid site accessibility. Compared with the corresponding reference catalysts, the hierarchical pore structure of the zeolite can greatly improve the diffusion efficiency of the reaction species and the accessibility of acid sites, showing better catalytic activity, stability, and selectivity of the target product. In addition, the reasonable combination of the active sites of metal hydrogenation and zeolite cracking is also a challenge for the application of hierarchical zeolite in heavy oil hydrocracking.