TAP analysis of single and double peak responses during CO oxidation over Pt

Abstract

Critical phenomena in heterogeneous catalysis have attracted a considerable interest throughout history due to their intriguing dynamical complexity. The coordinated interplay of various phenomena, such as surface interactions, nonlinear reaction mechanisms and the transport of energy and mass, determine the likelihood of dynamic patterns in certain catalytic systems. In this work, pulse experiments performed with a Temporary Analysis of Products (TAP) reactor showcase the complex dynamic behavior of CO oxidation over a Pt catalyst and exhibit its dependence on the pulsed CO/O2 ratio and the local bed temperature. Pulse responses exhibit a dynamic transition between two critical values of the reaction rate for feed mixtures richer in O2 due to the controlled interactions of the adsorbed species on the surface of the catalyst.