State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China.
J Am Chem Soc. 2013 Jan 30;135(4):1506-15. doi: 10.1021/ja310498c. Epub 2013 Jan 11.
The use of a heterogeneous Lewis acid catalyst, which is insoluble and easily separable during the reaction, is a promising option for hydrolysis reactions from both environmental and practical viewpoints. In this study, ceria showed excellent catalytic activity in the hydrolysis of 4-methyl-1,3-dioxane to 1,3-butanediol in 95% yield and in the one-pot synthesis of 1,3-butanediol from propylene and formaldehyde via Prins condensation and hydrolysis reactions in an overall yield of 60%. In-depth investigations revealed that ceria is a water-tolerant Lewis acid catalyst, which has seldom been reported previously. The ceria catalysts showed rather unusual high activity in hydrolysis, with a turnover number (TON) of 260, which is rather high for bulk oxide catalysts, whose TONs are usually less than 100. Our conclusion that ceria functions as a Lewis acid catalyst in hydrolysis reactions is firmly supported by thorough characterizations with IR and Raman spectroscopy, acidity measurements with IR and (31)P magic-angle-spinning NMR spectroscopy, Na(+)/H(+) exchange tests, analyses using the in situ active-site capping method, and isotope-labeling studies. A relationship between surface vacancy sites and catalytic activity has been established. CeO(2)(111) has been confirmed to be the catalytically active crystalline facet for hydrolysis. Water has been found to be associatively adsorbed on oxygen vacancy sites with medium strength, which does not lead to water dissociation to form stable hydroxides. This explains why the ceria catalyst is water-tolerant.
从环境和实际角度来看，使用不溶性且易于在反应过程中分离的多相路易斯酸催化剂是水解反应的一种很有前途的选择。在这项研究中，氧化铈在 4-甲基-1,3-二恶烷水解为 1,3-丁二醇的反应中表现出优异的催化活性，产率为 95%；在丙烯和甲醛通过 Prins 缩合和水解反应一锅法合成 1,3-丁二醇的反应中，产率为 60%。深入研究表明，氧化铈是一种耐水的路易斯酸催化剂，以前很少有报道。氧化铈催化剂在水解反应中表现出相当异常的高活性，转化率（TON）为 260，这对于体相氧化物催化剂来说相当高，其 TON 通常小于 100。我们的结论是，氧化铈在水解反应中作为路易斯酸催化剂起作用，这一结论得到了彻底的红外和拉曼光谱、红外和（31）P 魔角旋转 NMR 光谱酸度测量、Na(+)/H(+)交换测试、原位活性位封端方法分析以及同位素标记研究的有力支持。建立了表面空位与催化活性之间的关系。已经证实 CeO(2)(111)是水解的催化活性晶面。发现水与中等强度的氧空位缔合吸附，不会导致水离解形成稳定的氢氧化物。这解释了为什么氧化铈催化剂是耐水的。
