Cooperative effects in heterogeneous catalysis. Part 2.—Analysis and modelling of the temperature dependence of the oscillating catalytic oxidation of CO on a palladium Al2O3-supported catalyst

Abstract

The temperature dependence of the dynamics of the heterogeneous oxidation of CO on palladium supported by an amorphous Al₂O₃ carrier has been studied. The complex structure of the observed time series has been investigated by fast-Fourier-transform analysis. The resulting spectra are characterized by at most three frequencies, the ratio of which is nearly an integer, and by frequency locking. For lower temperatures sub-harmonics of these frequencies become important. The fractal character of the time series could be explained qualitatively by a one-dimensional automaton representing a concentration wave travelling on a fractal network of Pd particles in the catalyst bed.