ELECTROSTATIC-FIELD EFFECTS IN SURFACE REACTIVITY - ADSORPTION, DISSOCIATION AND CATALYTIC REACTION OF NITRIC-OXIDE

Pulsed field desorption mass spectrometry (PFDMS) is used to investigate dynamic processes in adsorption layers and the influence of electrostatic fields on surface reactivity. Long-range and short-range electrostatic field effects are discussed and the possibilities to study long-range effects by PFDMS are outlined. PFDMS measurements for the adsorption of nitric oxide on different metal surfaces are compared with those of other surface science techniques, such as molecular beam techniques, where sticking coefficients, precursor states, mean residence times and binding energies are determined. Advantages and disadvantages of different methods will be examined. PFDMS provides the unique opportunity to consider the electrostatic field strength as an independent intensive property of a reactive system. Electrostatic field effects have been measured and will be discussed from a phenomenological point of view as well as in the frame of a microscopical theory. Experimental results on catalytic properties of K-doped platinum catalysts which are reported in the literature are compared with theoretical aspects of electrostatic field effects.