A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to...A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.展开更多
In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared a...In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared and the structures characterized by XRD, XPS and TEM. We determined that the obtained Pd–Cu/γ-Al2O3（molar ratio Pd：Cu = 5：1） was an efficient catalyst for the oxygenization of cyclopentene to cyclopentanone with 95% selectivity and 85% conversion（100 °C, 1 MPa initial O2 pressure, 7 h）.展开更多
Tandem catalysis for the hydrogenation rearrangement of furfural(FA)provides an attractive solution for manufacturing cyclopentanone(CPO)from renewable biomass resources.The Cu-Ni/Al-MCM-41 catalyst was synthesized an...Tandem catalysis for the hydrogenation rearrangement of furfural(FA)provides an attractive solution for manufacturing cyclopentanone(CPO)from renewable biomass resources.The Cu-Ni/Al-MCM-41 catalyst was synthesized and afforded excellent catalytic performance with 99.0%conversion and 97.7%selectivity to CPO in a near-neutral solution under 2.0 MPa H2 at 160℃ for 5 h,much higher than those on other molecular sieve supports including MCM-41,SBA-15,HY,and ZSM-5.A small amount of Al highly dispersed in MCM-41 plays an anchoring role and ensures the formation of highly dispersed CuNi bimetallic nanoparticles(NPs).The remarkably improved catalytic performance may be attributed to the bimetallic synergistic and charge transfer effects.In addition,the initial FA concentration and the aqueous system pH required precise control to minimize polymerization and achieve high selectivity of CPO.Fourier transform infrared spectroscopy and mass spectra results indicated that polymerization was sensitive to pH values.Under acidic conditions,FA and intermediate furfuryl alcohol polymerize,while the intermediate 4-hydroxy-2-cyclopentenone mainly polymerizes under alkaline conditions,blocking the cascade of multiple reactions.Therefore,near-neutral conditions are most suitable for minimizing the impact of polymerization.This study provides a useful solution for the current universal problems of polymerization side reactions and low carbon balance for biomass conversion.展开更多
N-benzyl-1-（5-（3-chlorophenyl）-1,3,4-oxadiazol-2-yl）cyclopentanamine was synthesized via one-pot reaction of appropriate benzylamine, cyclopentanone,（N-isocyanimino）triphenylphosphorane and m-chlorobenzoic acid....N-benzyl-1-（5-（3-chlorophenyl）-1,3,4-oxadiazol-2-yl）cyclopentanamine was synthesized via one-pot reaction of appropriate benzylamine, cyclopentanone,（N-isocyanimino）triphenylphosphorane and m-chlorobenzoic acid. The quantum theoretical calculations for crystal structure were performed by density functional theory（DFT/B3LYP/6-311＋G＊）. From the optimized structure, geometric parameters were obtained and experimental measurements were compared with the calculated data. Frontier molecular orbitals（FMOs）, total density of states（DOS）, molecular electrostatic potential（MEP）, molecular properties, natural charges, NMR parameters and NBO analysis for the product were investigated by theoretical calculations.展开更多
基金supported by the National Hi-tech Research and Development Program of China(863 Program)(2012AA051801)the Fundamenta lResearch Funds for the Central Universities(No.CXZZ13 0112)
文摘A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.
基金financial assistance from the National Natural Science Foundation of China (Nos. 21272050, 21371044, 21472033 and 21571047)
文摘In this work, Pd–Cu/γ-Al2O3 is prepared by the impregnation method and investigated for selective oxygenization of cyclopentene to cyclopentanone. A series of bimetallic Pd–Cu/γ-Al2O3 nanocatalysts were prepared and the structures characterized by XRD, XPS and TEM. We determined that the obtained Pd–Cu/γ-Al2O3（molar ratio Pd：Cu = 5：1） was an efficient catalyst for the oxygenization of cyclopentene to cyclopentanone with 95% selectivity and 85% conversion（100 °C, 1 MPa initial O2 pressure, 7 h）.
文摘Tandem catalysis for the hydrogenation rearrangement of furfural(FA)provides an attractive solution for manufacturing cyclopentanone(CPO)from renewable biomass resources.The Cu-Ni/Al-MCM-41 catalyst was synthesized and afforded excellent catalytic performance with 99.0%conversion and 97.7%selectivity to CPO in a near-neutral solution under 2.0 MPa H2 at 160℃ for 5 h,much higher than those on other molecular sieve supports including MCM-41,SBA-15,HY,and ZSM-5.A small amount of Al highly dispersed in MCM-41 plays an anchoring role and ensures the formation of highly dispersed CuNi bimetallic nanoparticles(NPs).The remarkably improved catalytic performance may be attributed to the bimetallic synergistic and charge transfer effects.In addition,the initial FA concentration and the aqueous system pH required precise control to minimize polymerization and achieve high selectivity of CPO.Fourier transform infrared spectroscopy and mass spectra results indicated that polymerization was sensitive to pH values.Under acidic conditions,FA and intermediate furfuryl alcohol polymerize,while the intermediate 4-hydroxy-2-cyclopentenone mainly polymerizes under alkaline conditions,blocking the cascade of multiple reactions.Therefore,near-neutral conditions are most suitable for minimizing the impact of polymerization.This study provides a useful solution for the current universal problems of polymerization side reactions and low carbon balance for biomass conversion.
基金supported by the University of Zanjanthe grant NRF-2015-002423 of the National Research Foundation of Korea
文摘N-benzyl-1-（5-（3-chlorophenyl）-1,3,4-oxadiazol-2-yl）cyclopentanamine was synthesized via one-pot reaction of appropriate benzylamine, cyclopentanone,（N-isocyanimino）triphenylphosphorane and m-chlorobenzoic acid. The quantum theoretical calculations for crystal structure were performed by density functional theory（DFT/B3LYP/6-311＋G＊）. From the optimized structure, geometric parameters were obtained and experimental measurements were compared with the calculated data. Frontier molecular orbitals（FMOs）, total density of states（DOS）, molecular electrostatic potential（MEP）, molecular properties, natural charges, NMR parameters and NBO analysis for the product were investigated by theoretical calculations.
