Hybrid mesoporous silica MCM-41 (O-MCM-41) was prepared using γ-aminopropyltriethoxysilane (APTES) as spacer, tetraethoxysilane as precursor and 2-acetylpyridine as organic moiety. The heterogeneous palladium catalys...Hybrid mesoporous silica MCM-41 (O-MCM-41) was prepared using γ-aminopropyltriethoxysilane (APTES) as spacer, tetraethoxysilane as precursor and 2-acetylpyridine as organic moiety. The heterogeneous palladium catalyst (PdCl2 / O-MCM-41) was then prepared by reaction of the hybrid MCM-41 with PdCl2(PhCN)2. The products were characterized by means of IR, XRD, XPS and N2 adsorption-desorption isotherms. The catalytic properties of the supported catalyst in the oxidative carbonylation of phenol to diphenyl carbonate (DPC) were investigated. The yield of DPC and turnover number (TON) reached 5.8% and 29 mol DPC·mol Pd-1, and Pd loss was only 2.7% at 110 °C, 4.4 MPa for catalytic reaction of 5 h with 4.2wt% Pd loading, and molar ratio of phenol to Pd being 1000 in the presence of Cu2O and terahydrofuran (THF).展开更多
The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,th...The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,the biphenyl yield may reach 50%,showing its good potential to match the homogeneous catalyst in traditional Ullmann coupling reactions.Based on BET and XRD etc.characterizations,the relationship between the excellent catalytic properties of the Pd/MCM-41 and its structural characteristics was discussed briefly.展开更多
文摘Hybrid mesoporous silica MCM-41 (O-MCM-41) was prepared using γ-aminopropyltriethoxysilane (APTES) as spacer, tetraethoxysilane as precursor and 2-acetylpyridine as organic moiety. The heterogeneous palladium catalyst (PdCl2 / O-MCM-41) was then prepared by reaction of the hybrid MCM-41 with PdCl2(PhCN)2. The products were characterized by means of IR, XRD, XPS and N2 adsorption-desorption isotherms. The catalytic properties of the supported catalyst in the oxidative carbonylation of phenol to diphenyl carbonate (DPC) were investigated. The yield of DPC and turnover number (TON) reached 5.8% and 29 mol DPC·mol Pd-1, and Pd loss was only 2.7% at 110 °C, 4.4 MPa for catalytic reaction of 5 h with 4.2wt% Pd loading, and molar ratio of phenol to Pd being 1000 in the presence of Cu2O and terahydrofuran (THF).
文摘The nanostructured mesoporous Pd/MCM-41 catalyst was prepared by impregnation.This catalyst exhibited high activity and selectivity to piphenyl during Ullmann coupling reaction of iodobenzene.With Pd loading of 12%,the biphenyl yield may reach 50%,showing its good potential to match the homogeneous catalyst in traditional Ullmann coupling reactions.Based on BET and XRD etc.characterizations,the relationship between the excellent catalytic properties of the Pd/MCM-41 and its structural characteristics was discussed briefly.
