Regulation of catalyst acid sites and its effect on the deep hydrogenation performance of anthracene

Deep hydrogenation of polycyclic aromatic hydrocarbons (PAHs) in coal tar is an effective method to prepare coal-based high energy density fuel. Due to the unique electronic structure and steric hindrance effect, present catalysts show insufficient capacity for deep hydrogenation of PAHs. In addition, increasing the acidity of catalyst and reaction conditions will lead to the increase of cracking products and the decrease of selectivity of perhydro-products. In this study, Al-SBA15 and USY were used to prepare composite meso-microporous supports with moderate acidity by hydrothermal synthesis. The noble metal Pt was loaded on the composite acid support by equi-volume impregnation. The saturation hydrogenation performance of the synthesized composite catalyst for the model compound anthracene was studied. The results showed that the selectivity of perhydroanthracene could reach about 99% when Brønsted acid content was 144.4μmol/g. TEM and SEM results showed that the Pt/Al-SBA15+USY catalyst was rod-like after hydrothermal recombination with USY inside and Al-SBA15 outside. The composite support maintained the original pore size of about 9.6nm and 0.8nm, respectively. Pt nanoparticles had high dispersion and the optimal size was 3.03nm. Comparative analysis showed that the acid content of the composite support prepared by hydrothermal synthesis of Al-SBA15 and USY molecular sieve was lower than that of the molecular sieve support after direct mixing. Thus, the capacity of saturated hydrogenation was improved. © 2024 Chemical Industry Press Co., Ltd.. All rights reserved.