Effect of Thin SiO2 Film Coating Pd on Mesoporous Pd / SiO2 Catalyzing Hydrogenation of Anthraquinone to Prepare H2O2

Based on the background of the hydrogenation of anthraquinone to produce hydrogen peroxide,Pd / SiO2 catalyst was prepared using mesoporous spherical silica support with an average pore diameter of 12 nm by strong electrostatic adsorption (SEA)method,and Pd particles supported on the catalyst were coated with TEOS to prepare Pd@SiO2 / SiO2 spherical particle catalyst for anthraquinone hydrogenation as well. Compared with unmodified Pd / SiO2 spherical catalyst,Pd@SiO2 / SiO2 catalyst showed better hydrogenation activity,and the space-time yield was 16. 4% higher than that of Pd / SiO2 . Besides,it also exhibits 100% selectivity. The prepared Pd@SiO2 / SiO2 and Pd / SiO2 catalysts were characterized by physical adsorption (BET),powder X-ray diffraction (XRD),transmission electron microscopy (TEM),H2 -TPR,XPS. After coating,it can be seen that the Pd particle surface has a thin SiO2 film of 0. 1 nm,and the specific surface area and pore volume of the catalyst increase,compared with the support,while the pore size decreases. The H2 -TPR and XPS characterization results show that,due to the coating of SiO2 film,the binding energy of Pd0 species on Pd@SiO2 / SiO2 is higher,and the interaction between Pd particles and carriers is stronger. The above methods make Pd@SiO2 / SiO2 catalyst shows higher selectivity and activity. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.