Although the oxidation of carbon monoxide on platinum is one of the oldest known catalytic reactions and one of the most thoroughly studied, it continues to pose difficulties and challenges to both the experimentalist and the theoretician. For the most part, these are due to the frequent observations of hysteresis, associated with steady-state multiplicity, and self-sustained oscillations in the reaction and to the fact that no generally accepted theoretical explanation for them is at hand. even though a large number of studies have addressed the subject.

Intrinsically Unstable Behavior during the Oxidation of Carbon Monoxide on Platinum

Publisher Summary This chapter focuses on the oscillatory catalytic reactions at single-crystal surfaces. Among oscillating chemical systems, catalytic reactions at well-defined single-crystal surfaces under low-pressure conditions are conceptually particularly attractive for the following reasons: The reacting medium is strictly two-dimensional and uniform on the mezoscopic length scale, which is relevant for spatial pattern formation. In addition, the low partial pressures cause only minor heat production by the reaction, so that usually isothermal conditions can be kept to within a very good approximation. By combining kinetic measurements with surface-sensitive techniques, it became possible to explore the elementary steps underlying the complex temporal and spatial effects in fair detail, which information, in turn, then could be used for theoretical modeling. For the systems described in the chapter, the following mechanisms is found to determine the occurrence of isothermal kinetic oscillations: (1) adsorbate driven structural transformation, (2) formation and depletion of a subsurface oxygen species, and (3) autocatalytic surface reaction.

Oscillatory Catalytic Reactions at Single-Crystal Surfaces

Multiplicities and instabilities in chemically reacting systems — a review

Kinetic oscillations in the catalytic CO oxidation on a Pt(110) surface

Oscillatory oxidation of Co over a Pt catalyst

This paper deals with the status of knowledge concerning open catalytic reaction systems which, though exposed to constant conditions, exhibit sustained oscillatory states. Such behavior arouses in...

H. A. Schmitz

Papers

Oscillations in Catalytic Reactions