Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
J Phys Chem A. 2011 Aug 11;115(31):8754-60. doi: 10.1021/jp204371g. Epub 2011 Jul 18.
The isomerization of glyceraldehyde to dihydroxy acetone catalyzed by the active site of Sn-beta zeolite is investigated using the B3LYP density functional and MP2 levels of theory. Structural studies were aimed to understanding the binding modes of glyceraldehyde with the active site, and the detailed free energy landscape was computed for the isomerization process. The rate-limiting step for the isomerization is the 1,2-hydride shift, which is enhanced by the active participation of the hydroxyl group in the hydrolyzed Sn-beta active site analogues to the one seen in the xylose isomerase. On the basis of the assessment of the activation barriers for isomerization by the Sn, Zr, Ti, and Si zeolite models, the activity of the catalysts are in the order of Sn > Zr > Ti > Si in aqueous dielectric media.
使用 B3LYP 密度泛函和 MP2 理论水平研究了 Sn-β沸石活性位催化甘油醛异构化为二羟丙酮。结构研究旨在了解甘油醛与活性位的结合模式，并计算异构化过程的详细自由能景观。异构化的速率限制步骤是 1,2-氢化物转移，水解的 Sn-β活性位类似物中的羟基的积极参与增强了这一步骤，这与木糖异构酶中观察到的过程类似。基于对 Sn、Zr、Ti 和 Si 沸石模型异构化活化能垒的评估，在水介电介质中，催化剂的活性顺序为 Sn > Zr > Ti > Si。
