AVS 49th International Symposium
    Applied Surface Science Thursday Sessions
       Session AS-ThA

Paper AS-ThA1
Transferring Classical UHV Techniques into Ambient Pressure - Is the Gap Bridged for Electrons?

Thursday, November 7, 2002, 2:00 pm, Room C-106

Session: Practical Surface Science II
Presenter: A. Vollmer, University of Cambridge, UK
Authors: A. Vollmer, University of Cambridge, UK
J.D. Lipp, Rutherford Appleton Laboratories, UK
G.E. Derbyshire, Rutherford Appleton Laboratories, UK
H. Weiss, Universit@um a@t Magdeburg, Germany
D. Herein, ACA, Berlin, Germany
T. Rayment, University of Cambridge, UK
Correspondent: Click to Email
Most traditional surface science methods are restricted to studies of model systems under 'ideal' conditions, most prominently single crystals in ultra-high vacuum (UHV). The interest in the development of surface science methods for investigations of systems with a more immediate, practical relevance (e.g., heterogeneous catalysts) remains strong, especially with a view to the difficulties in delineating relationships between interfacial behaviour under conventional "surface science" and "practical" conditions, i.e. high pressure environments. In the field of heterogeneous catalysis the terms "pressure gap" and "material gap" have been coined to describe the relationship between surface science and practical catalysis. Under UHV conditions, gas-surface-interactions are widely studied by means of electron detection (LEED, UPS, XPS, XAS and many more) while in gaseous environments electrons are strongly scattered and quickly attenuated. Until recently,@footnote 1@ an efficient mode for energy-selective electron detection at ambient pressure was not available. We have now explored the possibilities of gas microstrip detectors (GMSD) as a promising tool for bridging the pressure gap between surface science and 'real world' conditions. We will show that energy-selective electron detection and depth profiling is possible for various systems operating under practical pressure conditions, including powders, layered structures, metals as well as insulators. Investigated systems include partial oxidation catalysts based on Vanadium oxides and phosphates. We will also report upon an ambient pressure surface sensitive scanning X-ray microprobe working under reaction conditions. @FootnoteText@ @footnote 1@ T. Rayment et al, Rev. Sci. Instrum. 71 (2000) 3640.