Fluctuations during catalytic CO oxidation on different crystal planes of a Pt field emitter

Abstract

Fluctuations during catalytic CO oxidation on the (100), (111) and (113) planes of the [100]-oriented Pt field emitter tip are studied by FEM (field electron microscope). Intensity profiles and local time series are obtained by digitizing the image brightness in a rectangular probing window oriented along the [110]-direction. From the local time series the probability density distributions as well as the auto- and cross-correlation functions are computed. The results demonstrate that the fluctuation behavior is quite different on the different facets of a field emitter tip. On the facets studied here, the fluctuations observed in the monostable and in the bistable region of the reaction exhibit substantial differences in the degree of time- and spatial correlation.