Synergistic Effects of Bimetallic PtPd/TiO2 Nanocatalysts in Oxidation of Glucose to Glucaric Acid: Structure Dependent Activity and Selectivity
Synergistic Effects of Bimetallic PtPd/TiO2 Nanocatalysts in Oxidation of Glucose to Glucaric Acid: Structure Dependent Activity and Selectivity
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DOI：
10.1021/acs.iecr.5b04841
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发表时间：
2016-03-23
影响因子：
4.2
通讯作者：
Chaudhari, Raghunath V.
中科院分区：
文献类型：
--
作者：
Jin, Xin;Zhao, Meng;Chaudhari, Raghunath V.
以PtPd/TiO 2为催化剂，在温和条件下，葡萄糖直接氧化为葡萄糖二酸，并生成丙醇二酸和草酸。双金属PtPd催化剂在葡萄糖氧化中显示出显著增强的催化活性（周转频率（TOP）2404 h（-1））和改进的对葡萄糖二酸的选择性（S 44%），相比于单金属催化剂（TOP 248 h（-1），S 4%）。葡萄糖的氧化遵循与作为中间体的葡萄糖酸的连续反应，葡萄糖的存在抑制了第二步（葡萄糖二酸和C-C裂解反应）。使用TEM，SEM，化学吸附，紫外可见光谱和XRD的表面表征区分颗粒形态，并提供了结构-活性关系的见解。根据产物分布，提出了葡萄糖氧化的反应途径。这些结果为葡萄糖氧化制葡萄糖二酸的催化剂设计提供了新的思路。
Direct oxidation of glucose with enhanced selectivity to glucaric acid with tartronic and oxalic acids as coproducts is reported using bimetallic PtPd/TiO2 catalysts under mild conditions. Bimetallic PtPd catalysts display significantly enhanced catalytic activity (turnover frequency (TOP) 2404 h(-1)) and improved selectivity to glucaric acid (S 44%) in glucose oxidation compared to monometallic catalysts (TOP 248 h(-1), S 4%). Oxidation of glucose follows a consecutive reaction with gluconic acid as an intermediate with inhibition of the second step (to glucaric acid and C-C cleavage reactions) by the presence of glucose. Surface characterization using TEM, SEM, chemisorption, UV-vis spectroscopy, and XRD distinguished the particle morphologies and provided insights into structure-activity relations. A reaction pathway for glucose oxidation is proposed based on the product distribution. These results provide new insights into the design of bimetallic catalysts for the oxidation of glucose to glucaric acid.