This article develops an experimental and theoretical kinetic analysis of ceria reduction using TPR experiments, considering both low and high surface area samples. From data in the existing literature on oxygen diffusion within the ceria lattice, it may be shown that spatial effects within ceria crystallites can be neglected for temperature ranges relevant to ceria reduction without risking significant errors. Moreover, oxygen transport seems not to be responsible for the qualitative changes in TPR profiles occurring on low and high surface area samples. We have developed a simple kinetic model that is able to predict the unimodal and bimodal shape of low and high surface area ceria with correct location of the main peaks. The model displays a satisfactory quantitative agreement with respect to the degree of reduction as a function of temperature. The model highlights the influence of the kinetic and thermodynamic properties of the material and of its textural changes with temperature (sintering). The model can be used to predict the outcome of TPR experiments over a broad range of specific surface areas.

A model for the temperature-programmed reduction of low and high surface area ceria

TROVARELLI, Alessandro;DE LEITENBURG, Carla;
2000

Abstract

This article develops an experimental and theoretical kinetic analysis of ceria reduction using TPR experiments, considering both low and high surface area samples. From data in the existing literature on oxygen diffusion within the ceria lattice, it may be shown that spatial effects within ceria crystallites can be neglected for temperature ranges relevant to ceria reduction without risking significant errors. Moreover, oxygen transport seems not to be responsible for the qualitative changes in TPR profiles occurring on low and high surface area samples. We have developed a simple kinetic model that is able to predict the unimodal and bimodal shape of low and high surface area ceria with correct location of the main peaks. The model displays a satisfactory quantitative agreement with respect to the degree of reduction as a function of temperature. The model highlights the influence of the kinetic and thermodynamic properties of the material and of its textural changes with temperature (sintering). The model can be used to predict the outcome of TPR experiments over a broad range of specific surface areas.
File in questo prodotto:
File Dimensione Formato  
12093115332712599.pdf

non disponibili

Tipologia: Altro materiale allegato
Licenza: Non pubblico
Dimensione 113.71 kB
Formato Adobe PDF
113.71 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11390/712692
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 258
  • ???jsp.display-item.citation.isi??? 256
social impact