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Spatiotemporal patterns during CO oxidation on Pt(100) at elevated pressures
Author(s) -
Lele Tanmay P.,
Pletcher Timothy D.,
Lauterbach Jochen
Publication year - 2001
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690470617
Subject(s) - oscillation (cell signaling) , front (military) , oxygen , partial pressure , catalysis , kinetic energy , chemistry , briggs–rauscher reaction , pattern formation , reaction rate , analytical chemistry (journal) , physics , meteorology , classical mechanics , biochemistry , organic chemistry , chromatography , biology , genetics
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/O 2 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.