Temporal Analysis of Products (TAP) Study of the Adsorption of CO, O2, and CO2 on a Au/Ti(OH)4* Catalyst

Abstract

Abstract The adsorption kinetics on Au/Ti(OH)4* (a newly developed Au catalyst, active for low-temperature CO oxidation) for CO, O2, and CO2 in the temperature range 298–473 K was determined by temporal analysis of products (TAP) technique. The response signals from the single-pulse TAP experiments were analyzed using a statistical approach, and they were fitted to analytical models in order to establish the adsorption/desorption parameters. The pulse response of a non-adsorbing gas (argon) was used as a “reference”. The experiments revealed that: CO molecules reversibly adsorbed on the catalyst surface; O2 molecularly adsorbed , irreversibly for high pulse intensities and reversibly for low pulse ones; CO2 molecules irreversibly adsorbed on the surface, probably as carbonates. This catalyst exhibited an apparent negative activation energy for irreversible adsorption of O2.