The Study On Application Of Metal-organic Frameworks MOF-5,MIL-120 And NCU-3 In Hydrogenation And Hydroxylation Reactions

Metal-organic frameworks (MOFs) are a novel kind of porous functional materials with periodic network structures, self-assembed with metal ions and organic ligands. There was an explosive growth of interest for their potential applications in gas storage, catalysis, separations, sensors and purification purpose. In particular, the catalysis has attracted great attentions among these applications, not only for their various porous structures and higher surface areas, but also because their catalytic activities sites could be rationally designed by introduced functional metal ions or organic ligands. In this paper, we used a kind of metal-organic frameworks with the good thermal stablity as the supporter in gas-solid reaction—benzene hydrogenation. And a unsaturated Cu-MOF was used to catalyze the liquid phase raction—hydroxylation of phenol.1. In the first part of this thesis, MOF-5, MIL-120 with the good thermal stability were used as the supporter for Ni catalyst. The catalysts were prepared by impregnation method and studied their catalytic performance in benzene hydrogenation. The results reveal that two novel catalysts possessed better catalytic activity than that of Ni/Al2O3. The catalysts were characterized by X-ray powder diffraction, H2-TPR and H2-TPD to explain the cause of active differences.2. In the second part of this thesis, a 2D layer metal-organic framework [Cu2 (BPTC)(Im)4(H2O)(DMF)]n (NCU-3) with unsaturated coordinated Cu(II) sites was applied to the hydroxylation of phenol after activating. The catalytic results indicate that NCU-3 exhibits an obvious activity (13% yeild for catechol and 11% for hydroquinone) for phenol hydroxylation at 40℃for 4 h with ethol:water=4:1 as the solvent. Compared to the control experiments where the free Cu(II) (from Cu(OAc)2 salt) has been utilized as the catalysts, NCU-3 shows the higher selectivity to diphenols(94%). This suggests that the coordinated environment of unsaturated coordinated Cu(Ⅱ) sites in the 2D layer play the key role in the phenol hydroxylation. And based on the results of this work and related literatures, we propose the possible reaction process for the formation of diphenols.