Kinetic Study of H2 Oxidation in the Preferential Oxidation of CO on a Nanosized Au/CeO2 Catalyst

Kinetic study of H-2 oxidation in the preferential oxidation (PROX) of CO was implemented over a nanosize Au/CeO2 catalyst in a temperature range 313-353 K. The Langmuir-Hinshelwood mechanism was proposed to be mainly responsible for H-2 oxidation, and CO oxidation can be accelerated by coadsorbed H at low temperatures. On the other hand, the water in the system has proved to suppress both CO and H-2 oxidation by increasing the energy bars. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) of CO adsorption on the Au surface indicates that linear CO-Au bond can be weakened in the presence of H-2; meanwhile, water can be a poison taking effects via the bonding of water and the lattice oxygen at the interface of Au/CeO2. The irreversible loss of activity during reaction may be caused by the reconstruction of Au particles, at least in part.