Journal of Catalysis, Vol.149, No.2, 278-291, 1994
N2O Reduction by Co over an Alumina-Supported Pt Catalyst - Forced Composition Cycling
The reaction dynamics of N2O reduction by CO over an alumina-supported catalyst have been examined using forced square-wave cycling of CO and N2O concentrations. The experiments were carried out using an isothermal recycle reactor operated at 499 K with various values of the cycling frequency and the phase angle between the two composition cycles. Time-average CO conversions as high as five times the steady-state conversion were attained during the forced feed cycling. The observed dynamic behavior of the system has been described by a kinetic model consisting of three elementary steps which incorporates two main features, namely, the adsorbate-induced Pt surface-phase transformation (1 x 1 <-> hex) and the self-exclusion of CO during adsorption on the Pt surface. The model was able to describe quantitatively the experimental results of the steady-state multiplicity behavior of the reaction. Thus, a simple model provides a consistent explanation for both the observed rate enhancement and dynamic CO, response during input cycling and the steady-state multiplicity
Keywords:CARBON-MONOXIDE OXIDATION;REACTION-RATE OSCILLATIONS;METAL-CATALYSTS;PT(100) SURFACE;NO REDUCTION;STEADY-STATE;PLATINUM;ADSORPTION;BEHAVIOR;SPECTROSCOPY