Jaramillo Donna M, Hunka Deborah E, Land Donald P
Department of Chemistry, University of California, Davis, California 95616, USA.
Langmuir. 2004 Jul 6;20(14):5782-5.
The reaction of cis-1,2-dichloroethene (cis-DCE) on Pd(111) has been investigated by temperature-programmed desorption, laser-induced thermal desorption, Auger electron spectroscopy, and Fourier transform reflection absorption infrared spectroscopy. Below 130 K, molecularcis-DCE aggregates, resulting in only about 30% of the molecules from exposures below saturation significantly interacting with the palladium surface. The decomposition of cis-DCE generates the observable species H2, HCl, and ethylidyne. A fraction of cis-DCE molecules lose both chlorine atoms and add hydrogen to form ethylidyne, which is stable on the surface between 250 and 370 K. Hydrogen is liberated at about 420 K from cis-DCE surface fragments that immediately combine with surface chlorine and desorb as HCl. The most intense HCl desorption occurs at about 575 K and is due to surface chlorine reacting with either subsurface hydrogen or hydrogen from the remaining surface alkyl fragments. No carbon-containing species desorb from the decomposition of cis-DCE.
通过程序升温脱附、激光诱导热脱附、俄歇电子能谱和傅里叶变换反射吸收红外光谱研究了顺式-1,2-二氯乙烯（顺式-DCE）在Pd(111)上的反应。在130K以下，分子态的顺式-DCE发生聚集，使得低于饱和暴露量的分子中只有约30%与钯表面发生显著相互作用。顺式-DCE的分解产生了可观测的物种H₂、HCl和次乙基。一部分顺式-DCE分子失去两个氯原子并加氢形成次乙基，次乙基在250至370K的表面上是稳定的。氢气在约420K时从顺式-DCE表面碎片中释放出来，这些碎片立即与表面氯结合并以HCl形式脱附。最强烈的HCl脱附发生在约575K，这是由于表面氯与次表面氢或剩余表面烷基碎片中的氢发生反应。顺式-DCE分解没有含碳物种脱附。
