The effect of reduction temperature on the hydrogen adsorption and Rh dispersion in a Rh/Ce0.68Zr0.32O2 catalyst with texturally stable Ce0.68Zr0.32O2 support was investigated. Rh dispersion data were also obtained from Rh particle size analyses made using high-resolution transmission electron microscopy (HRTEM) images. Comparison of the dispersion values obtained by using the two techniques showed that H2 adsorption at -80 °C is a suitable tool for the estimation of Rh dispersion at reduction temperature, Tred, ≤500°C. For Tred > 500°C. a partial suppression of H2 chemisorption was observed. However, after a mild reoxidation and low temperature reduction, the H2 adsorption capacity of these samples was regenerated and good agreement with the HRTEM data was again obtained.
Rhodium dispersion in a Rh/Ce0.68Zr0.32O2 catalyst investigated by HRTEM and H2 chemisorption
FORNASIERO, Paolo;KASPAR, JAN
2000-01-01
Abstract
The effect of reduction temperature on the hydrogen adsorption and Rh dispersion in a Rh/Ce0.68Zr0.32O2 catalyst with texturally stable Ce0.68Zr0.32O2 support was investigated. Rh dispersion data were also obtained from Rh particle size analyses made using high-resolution transmission electron microscopy (HRTEM) images. Comparison of the dispersion values obtained by using the two techniques showed that H2 adsorption at -80 °C is a suitable tool for the estimation of Rh dispersion at reduction temperature, Tred, ≤500°C. For Tred > 500°C. a partial suppression of H2 chemisorption was observed. However, after a mild reoxidation and low temperature reduction, the H2 adsorption capacity of these samples was regenerated and good agreement with the HRTEM data was again obtained.Pubblicazioni consigliate
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