School of Materials Science, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi, 923-1292, Japan.
ChemSusChem. 2011 Apr 18;4(4):542-8. doi: 10.1002/cssc.201000359. Epub 2011 Jan 26.
A hydrotalcite-supported platinum (Pt/HT) catalyst was found to be a highly active and selective heterogeneous catalyst for glycerol oxidation in pure water under atmospheric oxygen pressure in a high glycerol/metal molar ratio up to 3125. High selectivity toward glyceric acid (78 %) was obtained even at room temperature under air atmosphere. The Pt/HT catalyst selectively oxidized the primary hydroxyl group of 1,2-propandiol to give the corresponding carboxylic acid (lactic acid) as well as glycerol. The activity of the catalyst was greatly influenced by the Mg/Al ratio of hydrotalcite. Glycerol conversion increased with increasing the Mg/Al ratio of hydrotalcite (from trace to 56 %). X-ray absorption fine structure (XAFS) measurements indicated that the catalytic oxidation activity was proportional to the metallic platinum concentration, and more than 35 % of metallic platinum was necessary for this reaction. TEM measurements and titration analysis by using benzoic acid suggested that the solid basicity of hydrotalcite plays important roles in the precise control of platinum size and metal concentration as well as the initial promotion of alcohol oxidation.
一种水滑石负载的铂（Pt/HT）催化剂被发现是一种在大气氧压下，在高甘油/金属摩尔比高达 3125 的纯水中，用于甘油氧化的高活性和选择性的多相催化剂。即使在室温下、空气气氛中，也能获得高选择性的甘油酸（78%）。Pt/HT 催化剂选择性地氧化 1,2-丙二醇的伯羟基，得到相应的羧酸（乳酸）和甘油。催化剂的活性受水滑石的 Mg/Al 比的影响很大。甘油转化率随着水滑石的 Mg/Al 比的增加（从痕量到 56%）而增加。X 射线吸收精细结构（XAFS）测量表明，催化氧化活性与金属铂的浓度成正比，而对于该反应，需要超过 35%的金属铂。TEM 测量和使用苯甲酸的滴定分析表明，水滑石的固体碱性在精确控制铂的尺寸和金属浓度以及初始促进醇氧化方面起着重要作用。
