Ru Nanoparticles Entrapped In Mesopolymers For Efficient Catalytic Hydrogenation

The well-ordered mesopolymers materials are a class of advanced materials, which possess the textural porosities of mesoporous materials with high specific surface area, well-ordered mesopores and tunable structures and simultaneously possess the merits of organic polymers with high hydrophobicity, easy functionalization, high stability in acid or base media in comparison to silica-base materials. FDU-type mesopolymer materials are a class of newly-developed advanced materials, with three-dimensional connected benzene-ring framework, large surface area and uniform pore sizes, can be derived from resols precursor (phenol/formaldehyde) with triblock copolymers via a solvent evaporation self-assembly (EISA), or through a simple dilute auqoues strategy. They are stable even under acidic and basic conditions. They also exhibit unique hydrophobic affinity towards organic reactants or solvents, quite different from their silica-based inorganic analogues. However, the application of FDU-type PMRs in catalysis has been rarely reported up to now.In the first part of this thesis, ruthenium nanoparticles entrapped in the periodic mesopolymers FDU-15 were prepared by simple impregnation, alcohothermal method and reduced by H2, C2H5OH and NaCOOH. Ru particles for all catalysts were well dispersed on the surface of FDU-type mesopolymers. The average Ru particle size for Ru/FDU-15-H2 and Ru/FDU-15-NaCOOH catalysts is about 1.7-1.8 nm, whereas the average Ru particle size for Ru/FDU-15-C2H5OH and Ru/FDU-15-alcohothermal catalysts is about 3.8 nm. The TPR studies of all Ru/FDU-15 catalysts showed that Ru precursor (RuCl3) of Ru/FDU-15-H2, Ru/FDU-15-C2H5OH and Ru/FDU-15-alcohothermal were thoroughly reduced to metallic, whereas the Ru/FDU-15-NaHCOO catalyst still contained some Ru3+ species after reduction. The Ru/FDU-15-H2 catalyst showed highest conversion (71%) and selectivity (93%) for benzaldehyde hydrogenation among all the Ru/FDU-15 catalysts. The benzaldehyde hydrogenation on the Ru/FDU-15-H2 catalyst in water went faster than in ethanol, and the catalyst also can be reused for several times in water and in ethanol. Ru/FDU-15-H2 catalyst can also catalyze the hydrogenation of a series of benzaldehydes with different substituents at the phenyl ring with high performance. Except for catalyzing the benzaldehyde hydrogenation, the Ru/FDU-15-H2 catalyst can also catalyze the hydrogenation of arenes, olefins and some other carbonyl compounds. In all the investigated cases, the Ru/FDU-15-H2 catalyst showed a very high activity. The TOF of hydrogenation toluene reached 1213 h-1 in water, which was higher than previously reported.In the second part, we first time prepared the highly ordered Ru-containing mesopolymers materials and Ru-containing mesopolymer-silicon materials by one-pot synthesis. Our results demonstrated the catalyst of xRu-FDU-A had no well ordered mesostructures, and thus displayed poor catalysis for benzaldehyde hydrogenation. The self-assembly of xRu-FDU-E catalyst was not uniform, and accordingly showed inferior activity in the hydrogenation of benzaldehyde. The xRu-MPS catalysts had well ordered mesostructures, and Ru nanoparticles prepared with this one-pot method were highly dispersed on the mesoporous silicon, and consequently the xRu-MPS exhibited high activities in the hydrogenation of benzaldehyde.