Photocatalytic direct conversion of ethanol to 1,1- diethoxyethane over noble-metal-loaded TiO2 nanotubes and nanorods.
Photocatalytic direct conversion of ethanol to 1,1- diethoxyethane over noble-metal-loaded TiO2 nanotubes and nanorods.
复制标题
DOI：
10.1002/cssc.201403305
复制
发表时间：
2015-04
期刊：
影响因子：
8.4
通讯作者：
Hongxia Zhang;Yupeng Wu;Li Li-Li;Zhenping Zhu
中科院分区：
文献类型：
--
作者：
Hongxia Zhang;Yupeng Wu;Li Li-Li;Zhenping Zhu
作为最重要的生物质平台分子之一，乙醇需要对其产品链进行化学延伸，以满足未来对可再生燃料和化学品的需求。此外，在温和和绿色条件下乙醇的化学转化仍然是一个重大挑战。在这项工作中，乙醇直接转化为1，1-二乙氧基乙烷（DEE）和H2在温和的光催化条件下负载铂的二氧化钛纳米管和纳米棒。该反应遵循一个串联的缩合-缩醛化机理，即乙醇首先被光生空穴脱氢为乙醛和H（+）离子，然后乙醛和乙醇之间的缩醛化反应在真实的H（+）离子的促进下进行。过量的H（+）离子同时被光生电子还原成H2。该光催化过程在纳米级管状和棒状TiO 2光催化剂上具有非常高的反应速率，在相对低的光催化剂进料下达到157.7 mmol g（-1）h（-1）。更重要的是，该反应具有高度选择性，反应乙醇几乎按化学计量转化为DEE。这种乙醇的光催化脱氢C/O偶联是一种新的绿色途径，直接有效地将乙醇转化为DEE，并为可持续的生物乙醇应用提供了一个有前途的渠道。
As one of the most important biomass platform molecules, ethanol needs to have its product chain chemically extended to meet future demands in renewable fuels and chemicals. Additionally, chemical conversion of ethanol under mild and green conditions is still a major challenge. In this work, ethanol is directly converted into 1,1-diethoxyethane (DEE) and H2 under mild photocatalytic conditions over platinum-loaded TiO2 nanotubes and nanorods. The reaction follows a tandem dehydrogenation-acetalization mechanism, in which ethanol is first dehydrogenated into acetaldehyde and H(+) ion by photogenerated holes, and then acetalization between acetaldehyde and ethanol proceeds through promotion by H(+) ions formed in real time. Excess H(+) ions are simultaneously reduced into H2 by photogenerated electrons. This photocatalytic process has a very high reaction rate over nanosized tubular and rod-like TiO2 photocatalysts, reaching 157.7 mmol g(-1) h(-1) in relatively low photocatalyst feeding. More importantly, the reaction is highly selective, with a nearly stoichiometric conversion of reacted ethanol into DEE. This photocatalytic dehydrogenation CO coupling of ethanol is a new green approach to the direct efficient conversion of ethanol into DEE and provides a promising channel for sustainable bioethanol applications.