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
A novel environmental friendly catalyst, H4SiW12O40/PAn was prepared and identified by FT-IR, XRD and TG/DTA. The optimal synthetic protocol was a PAn to H4SiW12O40 mass ratio of 1 ： 1, a 20 mL of methanol and a reac...A novel environmental friendly catalyst, H4SiW12O40/PAn was prepared and identified by FT-IR, XRD and TG/DTA. The optimal synthetic protocol was a PAn to H4SiW12O40 mass ratio of 1 ： 1, a 20 mL of methanol and a reaction time of 2 h at reflux. It was used in catalytic synthesis of ten important ketals and acetals with a high catalytic activity. With an aldehyde/ketone to glycol molar ratio of 1 ： 1.5 and a 1 wt% catalyst loading, the yields of ketals and acetals could reach 60.0%- 93.8 % after 1 h.展开更多
Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial ...Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.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%.
基金Funded by the Natural Science Foundation of Hubei Province (No.2005ABA053)Hubei Key Laboratory of Pollutant Analysis & Reuse Technologythe National Natural Science Foundation of China (No. 20471044)
文摘A novel environmental friendly catalyst, H4SiW12O40/PAn was prepared and identified by FT-IR, XRD and TG/DTA. The optimal synthetic protocol was a PAn to H4SiW12O40 mass ratio of 1 ： 1, a 20 mL of methanol and a reaction time of 2 h at reflux. It was used in catalytic synthesis of ten important ketals and acetals with a high catalytic activity. With an aldehyde/ketone to glycol molar ratio of 1 ： 1.5 and a 1 wt% catalyst loading, the yields of ketals and acetals could reach 60.0%- 93.8 % after 1 h.
文摘Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.
