In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier tr...In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.展开更多
Samarocene complex was supported on a series of mesoporous silica with various pore sizes. Polymerization of methyl methacrylate (MMA) by these catalysts provide highly syndiotactic PMMAs with higher molecular weights...Samarocene complex was supported on a series of mesoporous silica with various pore sizes. Polymerization of methyl methacrylate (MMA) by these catalysts provide highly syndiotactic PMMAs with higher molecular weights compared with those obtained by solution polymerization with homogeneous catalyst system.展开更多
This paper reports mainly the preparation of silica supported acetylacetone ligands and their cobalt complexes, the characterization of their chemical structure, and the evaluation of their catalytic activity in the r...This paper reports mainly the preparation of silica supported acetylacetone ligands and their cobalt complexes, the characterization of their chemical structure, and the evaluation of their catalytic activity in the reaction for the preparation of ethers directly from alkanols and benzyl chloride. The results indicate that those silica supported β-diketone cobalt complexes (SACO) not only can simplify the reaction procedure of the ether preparation but also show a much higher catalytic activity in comparison with other homogeneous catalysts. In addition, SACO can be recovered and reused although their catalytic activity descend gradually as a result of the decrease in their cobalt content.展开更多
The hydrogenation of toluidines catalyzed by silica-supported carboxymethyl cellulose platinum complex forms methylcyclohexlamines in high yields, such as m-toluidine to 3-methylcyclohexylamine, o-toluidine to 2-methy...The hydrogenation of toluidines catalyzed by silica-supported carboxymethyl cellulose platinum complex forms methylcyclohexlamines in high yields, such as m-toluidine to 3-methylcyclohexylamine, o-toluidine to 2-methylcyclohexylamine, and p-toluidine to 4-methylcyclohexylamine in 97%, 96.7% and 98.2% yields, respectively, at 30 ℃ and under atmospheric hydrogen pressure. The yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. The catalyst was very stable and could be reused several times without remarkable change in the catalytic activity.展开更多
A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO_2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The ...A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO_2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The results showed that this catalystcould catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclo-hexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclo-hexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO_2-CMC-Pt has much influence on the initial hydrogenation rate andthe selectivity for the intermediate product, cyclohexanone. The highest initial rate andthe highest yield of cyclohexanone both occur at COO/Pt ratio of 6. The complex is stableduring the reaction and can be used repeatedly.展开更多
A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed t...A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed that the catalyst could catalyze the reaction in95.6% conversion with 92.8% selectivity for the normal aldehyde, methyl β-formylisobu-tyrate. Such catalyst also showed high stability during the reaction and could be used repeat-edly.展开更多
A natural polymer catalyst, silica-supported chitosan palladium complex (abbr. as SiO2-CS-Pd) was found to catalyze the hydrogenation of phenol and cresols to corresponding cyclohexanones in high yield and 100% select...A natural polymer catalyst, silica-supported chitosan palladium complex (abbr. as SiO2-CS-Pd) was found to catalyze the hydrogenation of phenol and cresols to corresponding cyclohexanones in high yield and 100% selectivity at 70 degrees C and 1.01325 x 10(5) Pa mild conditions. N/Pd molar ratio in the complex, temperature and solvents have much influence on the reaction. The reactivity order of reactants was found to be: phenol >m->p->o- The catalyst is stable during the reaction and could be repeatedly used for several times without much decrease in its catalytic activity.展开更多
A macroporous silica-based silver loaded adsorbent was synthesized by grafting the silver complexes of thiourea(Ag(tu)3NO3) into a silica-based copolymer support(Si O2-P). The adsorbent was used to uptake iodide anion...A macroporous silica-based silver loaded adsorbent was synthesized by grafting the silver complexes of thiourea(Ag(tu)3NO3) into a silica-based copolymer support(Si O2-P). The adsorbent was used to uptake iodide anions(I–) by batch and column techniques. The kinetic and saturated adsorption experiments were carried out by varying the shaking times and initial concentration of I–. Experimental results shown that the kinetic adsorption of I–was controlled by a pseudo second order model and the saturated adsorption of I–was controlled by the chemisorption mechanism, which followed a Langmuir adsorption equation. The breakthrough curve of I–had a S-shaped profile. The column efficiency was estimated to be over 90%.展开更多
基金Supported by the National Natural Science Foundation of China （20901063） the Natural Science Foundation of Hubei Province （2011CDB221）
文摘In this manuscript, a series of catalyst SG n-[VVO2-PAMAM-MSA] (SG silica gel, PAMAM polyamidoamine, MSA 5-methyl salicylaldehyde, n=0, 1, 2, 3) was prepared and their structures were fully characterized by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and inductive coupled plasma emission spectrometer (ICP) etc. XPS revealed that the metal V and SG n-PAMAM-MSA combined more closely after the formation of Schiff base derivatives. Their catalytic activities for oxidation of dibenzothiophene were evaluated using tert-butyl hydroperoxide as oxidant. The results showed that the catalyst SG 2.0-[VVO2-PAMAM-MSA] presented good catalytic activity and recycling time. Meanwhile, the optimal condition for the catalytic oxidation of SG 2.0-[VVO2-PAMAM-MSA] was also investigated, which showed that when the oxidation temperature was 90 °C, time was 60 min, the O/S was 3:1, and the mass content of catalyst was 1%, the rate of desulfurization could reach 85.2%. Moreover, the catalyst can be recycled several times without significant decline in catalytic activity.
基金The authors are grateful to the financial support from the National Natural Science Foundation of Chinathe Japan Society for the Promotion of Science(joint project No.20011894).
文摘Samarocene complex was supported on a series of mesoporous silica with various pore sizes. Polymerization of methyl methacrylate (MMA) by these catalysts provide highly syndiotactic PMMAs with higher molecular weights compared with those obtained by solution polymerization with homogeneous catalyst system.
文摘This paper reports mainly the preparation of silica supported acetylacetone ligands and their cobalt complexes, the characterization of their chemical structure, and the evaluation of their catalytic activity in the reaction for the preparation of ethers directly from alkanols and benzyl chloride. The results indicate that those silica supported β-diketone cobalt complexes (SACO) not only can simplify the reaction procedure of the ether preparation but also show a much higher catalytic activity in comparison with other homogeneous catalysts. In addition, SACO can be recovered and reused although their catalytic activity descend gradually as a result of the decrease in their cobalt content.
文摘The hydrogenation of toluidines catalyzed by silica-supported carboxymethyl cellulose platinum complex forms methylcyclohexlamines in high yields, such as m-toluidine to 3-methylcyclohexylamine, o-toluidine to 2-methylcyclohexylamine, and p-toluidine to 4-methylcyclohexylamine in 97%, 96.7% and 98.2% yields, respectively, at 30 ℃ and under atmospheric hydrogen pressure. The yields were remarkably affected by the Pt content in the complex, the kind of solvent and the reaction temperature. The catalyst was very stable and could be reused several times without remarkable change in the catalytic activity.
文摘A silica-supported carboxymethylcellulose platinum complex (abbreviated as SiO_2-CMC-Pt) has been prepared and characterized by XPS. Its catalytic properties for hydro-genation of aromatic compounds were studied. The results showed that this catalystcould catalyze the hydrogenation of phenol, anisol, p-cresol, benzene and toluene to cyclo-hexanol, cyclohexyl methyl ether, p-methyl cyclohexanol, cyclohexane and methylcyclo-hexane, respectively in 100% yield at 30℃ and 1 atm. In the hydrogenation of phenol,COO/Pt ratio in SiO_2-CMC-Pt has much influence on the initial hydrogenation rate andthe selectivity for the intermediate product, cyclohexanone. The highest initial rate andthe highest yield of cyclohexanone both occur at COO/Pt ratio of 6. The complex is stableduring the reaction and can be used repeatedly.
文摘A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed that the catalyst could catalyze the reaction in95.6% conversion with 92.8% selectivity for the normal aldehyde, methyl β-formylisobu-tyrate. Such catalyst also showed high stability during the reaction and could be used repeat-edly.
文摘A natural polymer catalyst, silica-supported chitosan palladium complex (abbr. as SiO2-CS-Pd) was found to catalyze the hydrogenation of phenol and cresols to corresponding cyclohexanones in high yield and 100% selectivity at 70 degrees C and 1.01325 x 10(5) Pa mild conditions. N/Pd molar ratio in the complex, temperature and solvents have much influence on the reaction. The reactivity order of reactants was found to be: phenol >m->p->o- The catalyst is stable during the reaction and could be repeatedly used for several times without much decrease in its catalytic activity.
基金Supported by National Natural Science Foundation of China(Nos.21261140335 and 91126006)the Scientific Research Foundation for Youth Scholars of Shanghai Jiao Tong University(No.AF0200003)
文摘A macroporous silica-based silver loaded adsorbent was synthesized by grafting the silver complexes of thiourea(Ag(tu)3NO3) into a silica-based copolymer support(Si O2-P). The adsorbent was used to uptake iodide anions(I–) by batch and column techniques. The kinetic and saturated adsorption experiments were carried out by varying the shaking times and initial concentration of I–. Experimental results shown that the kinetic adsorption of I–was controlled by a pseudo second order model and the saturated adsorption of I–was controlled by the chemisorption mechanism, which followed a Langmuir adsorption equation. The breakthrough curve of I–had a S-shaped profile. The column efficiency was estimated to be over 90%.
