首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Acetaldehyde adsorption and catalytic decomposition on Pd(1 1 0) and the dissolution of carbon
Authors:Michael Bowker  Richard Holroyd  Neil Perkins  Jenita Bhantoo  Albert Carley
Institution:a Wolfson Nanoscience Laboratory, School of Chemistry, Cardiff University, Cardiff CF10 3AT, Wales, UK
b Department of Chemistry, University of Reading, Reading RG6 6AD, UK
Abstract:The reaction of acetaldehyde with the Pd(1 1 0) surface has been studied using a molecular beam reactor, TPD and LEED. Below 270 K acetaldehyde sticks to the surface with a high initial probability (∼0.8), but no gas phase products evolve. When the reaction is run at >270 K, hydrogen evolves into the gas phase early in the reaction together with methane in a non-steady-state fashion, but above 300 K there is a very efficient steady-state catalytic reaction at the surface; this reaction is the decarbonylation of acetaldehyde to produce methane and carbon monoxide in the gas phase. This behaviour continues up to about 400 K. However, when acetaldehyde is dosed at 423 K, the reaction rate slowly evolves through a maximum to a very low catalytic rate. Upon carrying out reactor experiments at 473 K and above, the reaction mechanism changes to total dehydrogenation, and CO and H2 are produced at high steady-state rate, not withstanding the fact that carbon is continually being deposited onto the surface. This carbon does not appear to affect the reaction, which takes place on a surface with a c(2 × 2)-C layer present, since the extra carbon is lost from the reaction zone by diffusion into the bulk of the crystal.
Keywords:Acetaldehyde adsorption  Sticking  Pd(1     0)  Decarbonylation  Carbidation  Molecular beam
本文献已被 ScienceDirect 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号