Spatiotemporal Patterns During CO Oxidation on Pt(100) at Elevated Pressures

Document Type


Subject Area(s)

Engineering, Chemical Engineering, Catalysis and Reaction Engineering, Physical Sciences and Mathematics, Engineering Physics


CO oxidation on Pt(100) was investigated at reactant pressures of 8 Pa using ellipsomicroscopy for surface imaging to monitor spatiotemporal pattern formation on the catalyst surface and mass spectroscopy to monitor the integral reaction rate. Three distinct temperature regions showing nonlinear phenomena were found. The first region, at 540–615 K, is characterized by macroscopic, regular reaction-rate oscillations with spatially uniform, instantaneous transitions between CO and oxygen covered states. Regular, periodic oscillations were not observed on Pt(100) before. The second region, 480–540 K, exhibited continuous dynamic pattern formation with no visible macroscopic kinetic oscillations. Front speeds measured indicated a decrease in oxygen front velocity and an increase in CO front velocity with an increasing CO/O2 partial pressure ratio. The third region, 390–430 K, is characterized by macroscopic rate oscillations, which continued for several oscillation periods and then ceased with the onset of pattern formation.

Digital Object Identifier (DOI)

APA Citation

Lele, P.T., Pletcher, D.T., Lauterbach, A.J. (2001). Spatio-temporal pattern formation during CO oxidation on Pt(100) at elevated pressures. AIChE Journal, 47(6), 1418-1425.