Abstract In order to solve the low mechanical strength and poor structure stability of catalysts, a three-strand parallel flow method was proposed to prepare silica-containing pseudo-boehmite precursor. The microsphere SiO2-Al2O3 carrier with different silicon contents was obtained by spray drying with the precursor. Then Pd/SiO2-Al2O3 catalyst was further prepared by impregnation method and applied in the hydrogenation process of anthraquinone in the fluidized bed. It was found that the three-strand parallel flow drop addition method could make the silicon atoms evenly dispersed in the primary particles and the layered structure pseudo-boehmite formed by subsequent crystallization, which effectively solved problems of the silicon enrichment in the carrier and the blockage of the pore channels. With the introduction of silicon, the wear resistance and hydrothermal stability of the microsphere SiO2-Al2O3 were significantly improved. The structure characterization of Pd/SiO2-Al2O3 catalyst and the evaluation of anthraquinone hydrogenation performance showed that the average hydrogenation efficiency of the catalyst was 15.1 g/L and the production efficiency of H2O2 was up to 6 040 kg/(kg-Pd·d) when the mass fraction of SiO2 in Pd/SiO2-Al2O3 catalyst was 8%, and the selectivity was kept above 98.5%.
