| Abstract Three kinds of tungstozincic heteropoly acid complexes with Keggin structure,such as K_8[CdZnW_(11)O_(39)(H_2O)],K_8[NiZnW_(11)O_(39)(H_2O)],K_8[CuZnW_(11)O_(39)(H_2O)],were synthesized.Ethyl acetate was prepared from glacial acetic acid and anhydrous ethanol catalyzed by tungstozincic heteropoly acid complexes.The effects of molar ratio of anhydrous ethanol to glacial acetic acid,dosage of catalyst,reaction temperature and reaction time on the esterification ratio and reuse of catalyst were discussed.The results showed the optimal condition is that the Molar ratio of ethanol to acetic acid is 2��1, the dosage of catalyst is 1% of the material gross,reaction time is 6.0 h at 80 ��.Moreover,after continuous use for five times,the activity of the catalyst hardly descend. |
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2008, Vol. 25 
