Preparation of Solid Superacid SO42-/ZnO-TiO2 and Its Action on Synthesis of Dimethyl Carbonate from Urea and Methanol

Document Type : Research Article

Authors

1 College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu, 730070, P.R. CHINA

2 College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu, 730070, P.R. CHINA

Abstract

SO42-/ZnO-TiO2 catalyst was prepared by sulfating ZnO-TiO2 powders with H2SO4 solution. The catalyst was characterized by XRD, IR and Hammett indicator. The catalyst showed strong acidity(H0 -16.0). The optimum conditions are found that the calcination temperature is 823K and the soaked consistency of H2SO4 is 1 mol/dm3. Then SO42-/ZnO-TiO2 was applied as the catalyst in the catalytic synthesis of dimethyl carbonate(DMC) from urea and methanol under the optimum conditions and revealed higher catalytic activity. On condition that the reaction time is 6h, the reaction temperature is 433K, the mass percent of the catalyst used in the reactants is 5wt.%, and the molar ratio of methanol to urea is 14, the yields of DMC can reach 27.9%.

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Main Subjects


[1] Ono Yoshio, Dimethyl Carbonate for Environmentally Benign Reactions, Catalysis Today, 35, p. 15 (1997).
[2]  Bolun Yang, Dongpeng Wang, Hongye Lin, Jianjun Sun, Xiaoping Wang, Synthesis of Dimethyl Carbonate from Urea and Methanol Catalyzed by the Metallic Compounds at Atmospheric Pressure, Catalysis Communications, 7, p. 472 (2006).
[3] Mouhua Wang, Ning Zhao, Wei Wei, and Yuhan Sun. Synthesis of Dimethyl Carbonate from Urea and Methanol over ZnO, Ind. Eng. Chem. Res., 44, p. 7596 (2005).
[4] Ian J. Drake, Kyle L. Fujdala, Alexis T. Bell, T. Don Tilley, Dimethyl Carbonate Production via the Oxidative Carbonylation of Methanol Over Cu/SiO2 Catalysts Prepared via Molecular Precursor Grafting and Chemical Vapor Deposition Approaches, Journal of Catalysis, 230, p. 14 (2005).
[5] Hongyou Cui, Tao Wang, Fujun Wang, Chaoran Gu, Peilin Wang, Youyuan Dai,  Kinetic Study on the One-Pot Synthesis of Dimethyl Carbonate in Supercritical CO2 Conditions, Ind. Eng. Chem. Res., 43, p. 7732 (2004).
[6] Tuan-Chi Liu, Chung-Shin Chang, Preparation of CuCl/C Catalyst for the Synthesis of Dimethyl Carbonate: Effects of Calcination Temperature, Journal of the Chinese Institute of Chemical Engineers, 38, p. 29 (2007).
[7] Yoshio Ono, Catalysis in the Production and Reactions of Dimethyl Carbonate, an Environmentally Benign Building block, Applied Catalysis A 155, p. 133 (1997).
[8] Mouhua Wang, Hui Wang, Ning Zhao, Wei Wei, Yuhan Sun, Synthesis of Dimethyl Carbonate from Urea and Methanol Over Solid Base Catalysts, Catalysis Communications, 7, p. 6 (2006).
[9] Changcheng Wu, Xinqiang Zhao and Yanji Wang. Effect of Reduction Treatment on Catalytic Performance of Zn-Based Catalyst for the Alcoholysis of Urea to Dimethyl Carbonate, Catalysis Communications, 6, p. 694 (2005).
[10] Hongye Lin, Bolun Yang, Jianjun Sun, Xiaopin Wang, Dongpeng Wang, Kinetics Studies for the Synthesis of Dimethyl Carbonate from Urea and Methanol, Chemical Engineering Journal, 103, p. 21 (2004).
[11] Wu X.L., Xiao M., Meng Y.Z., Lu Y.X., Direct Synthesis of Dimethyl Carbonate on H3PO4 Modified V2O5, Journal of Molecular Catalysis A: Chemical, 238, p. 158 (2005).
[12] Xinchen Wang, Jimmy C. Yu, Ping Liu, Xuxu Wang, Wenyue Su, Xianzhi Fu, Probing of Photocatalytic Surface Sites on SO42/TiO2 Solid Acids by in situ FT-IR Spectroscopy and Pyridine Adsorption, Journal of Photochemistry and Photobiology A: Chemistry, 179, p. 339 (2006).
[13] Jianjun Sun, Bolun Yang, Xiaoping Wang, Dongpeng Wang and Hongye Lin. Synthesis of Dimethyl Carbonate from Urea and Methanol Using Polyphosphoric Acid as Catalyst, Journal of Molecular Catalysis A: Chemical, 239, p. 82 (2005).
[14] Wu X.L., Meng Y.Z, Xiao M., Lu Y.X., Direct Synthesis of Dimethyl Carbonate (DMC) Using Cu-Ni/VSO as Catalyst, Journal of Molecular Catalysis A: Chemical, 249, p. 93 (2006).