Kinetics of Hydrogen Chemisorption on high surface Area Pd/Ce0.8Zr0.2O2

F. GENNARI, C. NEYERTZ, G. MEYER, P. FORNASIERO Y M. GRAZIANO

Cracow, Polonia

Simposio; International Symposium on Metal-Hydrogen Systems: Fundamentals & Applications; 2004

Faculty of Physics and Nuclear Techniques, AGH University of Science and Technology, Department of Solid State Physics, Cracow, Polonia

The effect of H2 interaction with a 0.53%Pd/Ce0.8Zr0.2O2 sample was investigated by temperature-programmed reduction, dynamic oxygen-storage capacity (H2-OSC) and volumetric hydrogen measurements. The presence of Pd decreases the reduction temperature of the support and produces surface and bulk Ce4+/Ce3+ reduction. The H2-OSC shows that the surface could be fully saturated with hydrogen already at room temperature. In the 20-80°C range, the reduction rate was found to be dependent on temperature, while the total H2 uptake was constant. Increasing the reduction temperature results in an improvement of the subsequent H2 chemisorption rate due to spillover. In order to identify the Pd hydriding and support reduction processes, we present an analysis of the dependence of H2 chemisorption kinetics with pressure and temperature.