The adsorption, reaction and decomposition of a series of molecules (oxygen, ethylene, acetic acid, carbon monoxide and acetaldehyde) associated with vinyl acetate synthesis were investigated using a combination of ultra-high vacuum surface science techniques, including molecular beam sticking, x-ray photoelectron spectroscopy and temperature programmed desorption. The single crystal Pd (111) surface, bimetallic Au/Pd (111) surfaces prepared by metal vapour deposition and an alloyed Au30Pd70 (111) crystal were used in these studies. All the molecules investigated adsorbed onto the Pd (111) surface across a wide temperature range. Mechanisms for the reactions of each with the surface were suggested. The carbonaceous organic molecules all decomposed to deposit carbon at the surface at room temperature and above, blocking active sites to adsorption. Above a specific temperature, this carbon went subsurface and no longer inhibited subsequent adsorption of molecules. The deposited carbon could often be removed in a facile manner by oxygen treatment.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:584927 |
| Date | January 2010 |
| Creators | Counsell, Jonathan David Peter |
| Publisher | Cardiff University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://orca.cf.ac.uk/54930/ |
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