Physical Sciences Directorate and Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352, USA.
Phys Chem Chem Phys. 2013 Aug 7;15(29):12180-6. doi: 10.1039/c3cp50687h. Epub 2013 Jun 13.
The interactions of ethylene glycol with a partially reduced rutile TiO2(110) surface have been studied using temperature programmed desorption (TPD). The saturation coverage on surface Ti rows is determined to be 0.43 monolayer (ML), slightly less than one ethylene glycol per two Ti sites. Most of the adsorbed ethylene glycol (∼80%) undergoes further reactions to yield other products. Two major channels are observed, dehydration yielding ethylene and water and dehydrogenation yielding acetaldehyde and hydrogen. Hydrogen formation is rather surprising as it has not been observed previously on TiO2(110) from simple organic molecules. The coverage dependent yields of ethylene and acetaldehyde correlate well with those of water and hydrogen, respectively. Dehydration dominates at lower ethylene glycol coverages (<0.2 ML) and plateaus as the coverage is increased to saturation. Dehydrogenation is observed primarily at higher ethylene glycol coverages (>0.2 ML). Our results suggest that the observed dehydration and dehydrogenation reactions proceed via different surface intermediates.
采用程序升温脱附（TPD）技术研究了乙二醇与部分还原的锐钛矿 TiO2(110) 表面的相互作用。表面 Ti 位上的饱和覆盖度确定为 0.43 单层（ML），略小于每个 Ti 位上的一个乙二醇分子。吸附的大部分乙二醇（约 80%）进一步反应生成其他产物。观察到两个主要的反应通道，脱水生成乙烯和水，以及脱氢生成乙醛和氢气。氢气的形成是相当令人惊讶的，因为以前从未在 TiO2(110) 上从简单的有机分子中观察到过。乙烯和乙醛的产率随覆盖度的变化与水和氢气的产率分别很好地相关。在较低的乙二醇覆盖度（<0.2 ML）下，脱水反应占主导地位，随着覆盖度增加到饱和，其产率趋于平稳。在较高的乙二醇覆盖度（>0.2 ML）下，主要观察到脱氢反应。我们的结果表明，观察到的脱水和脱氢反应通过不同的表面中间体进行。
