Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cycl...Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cyclohexanone 1,2-propa- nediol ketal, butanone ethylene ketal, butanone 1,2-propanediol ketal, 2-phenyl-1,3-dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl-1,3-dioxolane, 4-methyl-2-propyl-1,3-dioxolane was reported. It has been demonstrated that activated carbon supported tungstosilicic acid is an excellent catalyst. Various factors involved in these reactions were investigated. The optimum conditions found were: molar ratio of aldehyde/ketone to glycol is 1/1.5, mass ratio of the catalyst used to the reactants is 1.0%, and reaction time is 1.0 h. Under these conditions, the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane is 61.5%, of 2,4-dimethyl- 2-ethoxycarbonylmethyl-1,3-dioxolane is 69.1%, of cyclohexanone ethylene ketal is 74.6%, of cyclohexanone 1,2-propanediol ketal is 80.1%, of butanone ethylene ketal is 69.5%, of butanone 1,2-propanediol ketal is 78.5%, of 2-phenyl-1,3-dioxolane is 56.7%, of 4-methyl-2-phenyl-1,3-dioxolane is 86.2%, of 2-propyl-1,3-dioxolane is 87.5%, of 4-methyl-2-propyl-1,3-dioxolane is 87.9%.展开更多
he perovskite-type PbTiO3 has been synthesized by the method of mixed oxides. The appropriate conditions for preparing have been reported. The obtained PbTiO3 powder is pure and fine. The decolorization of dyes in a ...he perovskite-type PbTiO3 has been synthesized by the method of mixed oxides. The appropriate conditions for preparing have been reported. The obtained PbTiO3 powder is pure and fine. The decolorization of dyes in a PbTiO3 suspension system is over 90%. In this paper the photocatalytic ability of PbTiO3 and the factors of influence are discussed.展开更多
The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town （MUCT） process. Meanwhile the relation between optimal...The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town （MUCT） process. Meanwhile the relation between optimal nitrate concentration （Nopt） and influent C/N ratio was evaluated, in which the influont chemical oxygen demand （COD） concentration was stabilized at （2905：10）mg/L, the influent total phosphorus （TP） concentration was stabilized at （7.0±0. 5）mg/L. The results indicated that： （1） the nitrate concentration in the main anoxic zone had an effect on denitrifying dephosphatation capability, and the average percentages of anoxic phosphorus uptake in total phosphorus uptake （ηa） increased with nitrate cancentration increasing, i.e., increasing from 62.1% at2.0 mg/L to63.7%, 65.6%, 68.1%, and 72.3% at 2.2, 2.4, 2.6 and 2.8mg/L, respectively; （2） the Nopt as function of influent C/N ratio could be calculated by the equation： y = 0.67x^2-7.79x ＋ 22. 21; the maximum percentages of anoxic phosphorus uptake in total phosphorus uptake （ηa,max） as function of the Nopt could be calculated by the equation： y=0.77-0.33e^-（x/1.52）. The Nopt was the important control parameter that must be optimized for operation of conveational biological nutrieat removal activated sludge （BNRAS） system.展开更多
A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silic...A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silica matrix. Further pyridine-FTIR spectra followed by catalytic activity tests demonstrate that compared with previous methods, our new approach results in higher Lewis acid site concentration, higher thermal stability and superior catalytic activity. Moreover, the whole catalysis preparation procedure is environmentally friendly. Specifically, the silica matrix is synthesized through hydrolysis of tetrae- thylorthosilicate employing formic acid as hydro-catalyst, in which no surfactant species or precursors were involved.展开更多
基金Project supported by the Natural Science Foundation of HubeiProvince Education Committee (No. 2004D007) and the NationalNatural Science Foundation of China (No. 20471044)
文摘Catalytic activity of activated carbon supported tungstosilicic acidin synthesizing 2-methyl-2-ethoxycarbonylmethyl- 1,3-dioxolane, 2,4-dimethyl-2-ethoxycarbonylmethyl-1,3-dioxolane, cyclohexanone ethylene ketal, cyclohexanone 1,2-propa- nediol ketal, butanone ethylene ketal, butanone 1,2-propanediol ketal, 2-phenyl-1,3-dioxolane, 4-methyl-2-phenyl-1,3-dioxolane, 2-propyl-1,3-dioxolane, 4-methyl-2-propyl-1,3-dioxolane was reported. It has been demonstrated that activated carbon supported tungstosilicic acid is an excellent catalyst. Various factors involved in these reactions were investigated. The optimum conditions found were: molar ratio of aldehyde/ketone to glycol is 1/1.5, mass ratio of the catalyst used to the reactants is 1.0%, and reaction time is 1.0 h. Under these conditions, the yield of 2-methyl-2-ethoxycarbonylmethyl-1,3-dioxolane is 61.5%, of 2,4-dimethyl- 2-ethoxycarbonylmethyl-1,3-dioxolane is 69.1%, of cyclohexanone ethylene ketal is 74.6%, of cyclohexanone 1,2-propanediol ketal is 80.1%, of butanone ethylene ketal is 69.5%, of butanone 1,2-propanediol ketal is 78.5%, of 2-phenyl-1,3-dioxolane is 56.7%, of 4-methyl-2-phenyl-1,3-dioxolane is 86.2%, of 2-propyl-1,3-dioxolane is 87.5%, of 4-methyl-2-propyl-1,3-dioxolane is 87.9%.
文摘he perovskite-type PbTiO3 has been synthesized by the method of mixed oxides. The appropriate conditions for preparing have been reported. The obtained PbTiO3 powder is pure and fine. The decolorization of dyes in a PbTiO3 suspension system is over 90%. In this paper the photocatalytic ability of PbTiO3 and the factors of influence are discussed.
基金Water Pollution Control and Management of Science and Technology Majon Projects (No.2008ZX07207005)The Programs for Development of Science and Technology of Jilin Province of China (No.20071105)
文摘The effects of nitrate concentration in the main anoxic zone on denitrifying dephosphatation capability were conducted based on modified University of Cape Town （MUCT） process. Meanwhile the relation between optimal nitrate concentration （Nopt） and influent C/N ratio was evaluated, in which the influont chemical oxygen demand （COD） concentration was stabilized at （2905：10）mg/L, the influent total phosphorus （TP） concentration was stabilized at （7.0±0. 5）mg/L. The results indicated that： （1） the nitrate concentration in the main anoxic zone had an effect on denitrifying dephosphatation capability, and the average percentages of anoxic phosphorus uptake in total phosphorus uptake （ηa） increased with nitrate cancentration increasing, i.e., increasing from 62.1% at2.0 mg/L to63.7%, 65.6%, 68.1%, and 72.3% at 2.2, 2.4, 2.6 and 2.8mg/L, respectively; （2） the Nopt as function of influent C/N ratio could be calculated by the equation： y = 0.67x^2-7.79x ＋ 22. 21; the maximum percentages of anoxic phosphorus uptake in total phosphorus uptake （ηa,max） as function of the Nopt could be calculated by the equation： y=0.77-0.33e^-（x/1.52）. The Nopt was the important control parameter that must be optimized for operation of conveational biological nutrieat removal activated sludge （BNRAS） system.
文摘A novel approach is designed to optimize the synthesis of sulfonic-functionalized silica material. Results from 29Si and 27AI NMR suggest that the AI acts as the bridging atom connecting the methanesulfonate and silica matrix. Further pyridine-FTIR spectra followed by catalytic activity tests demonstrate that compared with previous methods, our new approach results in higher Lewis acid site concentration, higher thermal stability and superior catalytic activity. Moreover, the whole catalysis preparation procedure is environmentally friendly. Specifically, the silica matrix is synthesized through hydrolysis of tetrae- thylorthosilicate employing formic acid as hydro-catalyst, in which no surfactant species or precursors were involved.
