This article proposes a novel decamethonium bromide-assisted method for modulating the size of supported metal nanoparticles in Pd/mesoporous HZSM-5 hydrodesulfurization (HDS) catalysts. The proposed approach significantly promotes the dispersion of supported palladium nanoparticles by bridging and anchoring the palladium precursor onto the surface of mesoporous HZSM-5 as well as restraining the subsequent aggregation of palladium nanoparticles in calcination. The as-prepared catalyst possessed higher 4,6-dimethyldibenzothiophene HDS activity than its counterpart that was prepared via impregnation due to its smaller Pd nanoparticles, higher Pd dispersion and higher content of Pd 0 species. This strategy provides a simple pathway for preparing supported metal nanoparticles with high dispersion.
Chemical upcycling of waste polyethylene terephthalate (PET) to value-added products can reduce the emission of CO 2 , microplastics and toxic chemicals. In this work, mesoporous H-type Zeolite Socony Mobil-5 (HZSM-5) supported Ru catalyst (Ru/ m -HZSM-5) was synthesized and tested in the hydrogenation of PET degraded chemicals (bis(2-hydroxyethyl) terephthalate , dimethyl terephthalate, diethyl terephthalate, and terephthalic acid). Characterizations disclosed that Ru/ m -HZSM-5 catalyst possesses mesopores (a dominant channel of 5.32 nm), enlarged specific surface area (404 m 2 ·g −1 ), and Ru NPs dispersed highly (40.6 %) compared to that of Ru/HZSM-5. And also, it was found that Ru/ m -HZSM-5 was capable for the hydrogenation of benzene rings in these PET degraded chemicals with large sizes (1.09–1.82 nm). In particular, the conversion of BHET and the selectivity of BHCD over Ru/ m -HZSM-5 reached 95.5 % and 95.6 % at 120 °C within 2 h. And Ru/ m -HZSM-5 could be recycled at least five times without obvious loss of activity and selectivity.