A PHOTOEMISSION ELECTRON-MICROSCOPY (PEEM) STUDY OF THE EFFECT OF SURFACE ACOUSTIC-WAVES ON CATALYTIC CO OXIDATION OVER PT(110)

A photoemission electron microscope (PEEM) was used to study the influ ence of surface acoustic waves (SAWs) on the reactive behaviour of ads orbate structures during CO oxidation over Pt{110} at temperatures aro und 485 K and CO and O-2 pressures around 10(-5) and 10(-4) mbar, resp ectively. It was found that surface acoustic wave excitation can suppr ess and reverse the process of CO poisoning of the catalyst, and thus bring the system back into the highly reactive regime. From work funct ion measurements of the CO-covered surface during acoustic excitation it is concluded that the observed effect is due to acoustically induce d CO desorption. (C) 1998 Elsevier Science B.V. All rights reserved.