Water-tolerant solid acid catalysis of Cs2.5H0.5PW12O40 for hydrolysis of esters in the presence of excess water
Water-tolerant solid acid catalysis of Cs2.5H0.5PW12O40 for hydrolysis of esters in the presence of excess water
复制标题
DOI：
10.1016/s0926-860x(97)00204-4
复制
发表时间：
1997-12-31
影响因子：
5.5
通讯作者：
Okuhara, T
中科院分区：
文献类型：
--
作者：
Kimura, M;Nakato, T;Okuhara, T
研究了在过量水存在下，乙酸乙酯、乙酸环己酯、乙酸2-甲基苯酯和乙酸2-硝基苯酯的水解反应。无机固体酸如12-钨磷酸的酸性铯盐Cs2.5H0.5PW12O40、H-ZSM-5、SO 42-/ZrO 2和Nb 2 O 5以及聚合物树脂Amberlyst-15、Amberlite-200 C和Nafion-H催化反应，而H-Y、H-丝光沸石、SiO2-Al 2 O3和γ-Al 2 O3无活性。在无机固体酸中，Cs2.5H0.5PW12O40对所有反应的活性最高，单位催化剂重量的活性。CS_（2.5）H_（0.5）PW_（12）O_（40）在单位酸量催化剂的催化活性方面与Nafion-H相当，比H-ZSM-5、SO_（4 -2）/ZrO_2和Amberlyst-15的活性高得多。H_2SO_4、H_3PW_（12）O_（40）和对甲苯磺酸等液体酸催化剂的单位酸量活性均低于Cs_（2.5）H_（0.5）PW_（12）O_（40），但相对于催化剂重量的相对活性高于Cs_（2.5）H_（0.5）PW_（12）O_（40）。对H-ZSM-5不活泼的乙酸2-甲苯酯和乙酸2-硝基苯酯的水解反应，Cs2.5H0.5PW12O40的催化活性明显高于其它催化剂，表明Cs2.5H0.5PW12O40是一种具有广泛应用前景的耐水性固体酸。当Cs2.5H0.5PW12O40从反应物溶液中分离出来并重复用于乙酸乙酯的水解时，第5次的反应速率大于第1次的90%，而SO 4 -2-/ZrO 2的反应速率在重复一次后下降到第1次的一半以下。(C)1997年Elsevier Science B.V.
Hydrolysis reactions of esters, ethyl acetate, cyclohexyl acetate, 2-methylphenyl acetate, and 2-nitrophenyl acetate in the presence of a large excess of water were investigated by using various solid acids. Inorganic solid acids such as an acidic cesium salt of 12-tungstophosphoric acid Cs2.5H0.5PW12O40, H-ZSM-5, SO42-/ZrO2, and Nb2O5, and polymer resins, Amberlyst-15, Amberlite-200C, and Nafion-H catalyzed the reactions, whereas H-Y, H-mordenite, SiO2-Al2O3, and gamma-Al2O3 were inactive. Among inorganic solid acids, Cs2.5H0.5PW12O40 was most active for all reactions in the unit of the activity per catalyst weight. CS2.5H0.5PW12O40 was comparable to Nafion-H in the catalytic activity per unit acid amount of catalysts, and much more active than H-ZSM-5, SO4-2/ZrO2, and Amberlyst-15. The activities of liquid acid catalysts, such as H2SO4, H3PW12O40, and p-toluenesulfonic acid, per unit acid amount were less than that of Cs2.5H0.5PW12O40, although the relative activities per catalyst weight of the liquid acids were higher than that of CS2.5H0.5PW12O40. The activity of Cs2.5H0.5PW12O40 relative to the other catalysts became higher for hydrolysis of bulky esters like 2-methylphenyl acetate and 2-nitrophenyl acetate for which H-ZSM-5 was inactive, demonstrating that CS2.5H0.5PW12O40 is a widely applicable water-tolerant solid acid. When Cs2.5H0.5PW12O40 was separated from the reactant solution and reused for the hydrolysis of ethyl acetate repeatedly, the reaction rate of the 5th run was more than 90% that of the 1st run, whereas the rate on SO4-2/ZrO2 decreased by repeating once to become less than half that of the 1st run. (C) 1997 Elsevier Science B.V.