Visible-Light-Controlled Oxidation of Glucose using Titania-Supported Silver Photocatalysts.
Visible-Light-Controlled Oxidation of Glucose using Titania-Supported Silver Photocatalysts.
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DOI：
10.1002/cctc.201600775
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发表时间：
2016-11-22
期刊：
影响因子：
4.5
通讯作者：
Lopez-Sanchez JA
中科院分区：
文献类型：
--
作者：
Da Vià L;Recchi C;Davies TE;Greeves N;Lopez-Sanchez JA
首次展示了使用 TiO2 支撑的银纳米粒子的可见光介导的光催化选择性葡萄糖增值。催化剂组成、底物与催化剂的比例和反应介质的优化证明，可以实现对矿化途径的几乎完全抑制，对部分氧化产物和小链单糖的选择性高达 98%。经测定，主要产物为葡萄糖酸、阿拉伯糖、赤藓糖、甘油醛和甲酸。在 UVA 光下，由于矿化过程中产生二氧化碳，对有机物的选择性降低。提出了一种基于α-断裂过程与Ruff降解反应相结合的反应机制，这解释了氧化产物、较小的碳水化合物和甲酸的存在。 X 射线光电子能谱、紫外/可见光谱和显微镜研究表明，存在等离激元 4 nm 银颗粒，这些颗粒在反应过程中被氧化成氧化银，回收研究表明这不会损害活性。
The visible‐light‐mediated photo‐catalytic selective valorisation of glucose using TiO2‐supported Ag nanoparticles is shown for the first time. The optimisation of the catalyst composition, substrate‐to‐catalyst ratio and reaction medium proved that a near total suppression of the mineralisation pathway could be achieved with a selectivity to partial oxidation products and small‐chain monosaccharides as high as 98 %. The primary products were determined to be gluconic acid, arabinose, erythrose, glyceraldehyde and formic acid. Under UVA light, the selectivity to organics decreases because of the production of CO2 from mineralisation. A reaction mechanism is proposed based on an α‐scission process combined with the Ruff degradation reaction, which explains the presence of the oxidation products, the smaller carbohydrates and formic acid. X‐ray photoelectron spectroscopy, UV/Vis spectroscopy and microscopy studies showed the presence of plasmonic 4 nm particles of silver that were oxidised to silver oxide over the course of the reaction, and recycling studies revealed that this was not detrimental to activity.