The influences of low-temperature redox cycling and of the presence of chloride on the redox and chemisorptive properties of Rh/Ce0.6Zr0.4O2 were investigated by means of volumetric hydrogen chemisorption, temperature-programmed reduction, and temperature-programmed desorption. This was achieved by conducting experiments on two samples of the material prepared from nitrate and chloride precursors. For the purposes of comparison, some parallel investigations were also conducted on the pure support. The results demonstrate that the interaction of Rh/Ce0.6Zr0.4O2 With hydrogen is critically dependent not only on the presence of chloride but also on the specific treatments applied to the sample. The most important effect of chloride is that it inhibits the extent of vacancy creation at common operating temperatures of working three-way catalysts, thereby highlighting the unsuitability of chloride-based preparations for such materials. While some chloride can be removed under the low-temperature cycling conditions employed, the extent of this removal is small, and a lower degree of reduction was attained by the chloride sample throughout the series of experiments.

Redox and chemisorptive properties of ex-chloride and ex-nitrate Rh/Ce0.6Zr0.4O2 catalysts Part 1: Effect of low temperature redox cycling.

FORNASIERO, Paolo;HICKEY, JAMES NEIL;KASPAR, JAN;GRAZIANI, MAURO
2000

Abstract

The influences of low-temperature redox cycling and of the presence of chloride on the redox and chemisorptive properties of Rh/Ce0.6Zr0.4O2 were investigated by means of volumetric hydrogen chemisorption, temperature-programmed reduction, and temperature-programmed desorption. This was achieved by conducting experiments on two samples of the material prepared from nitrate and chloride precursors. For the purposes of comparison, some parallel investigations were also conducted on the pure support. The results demonstrate that the interaction of Rh/Ce0.6Zr0.4O2 With hydrogen is critically dependent not only on the presence of chloride but also on the specific treatments applied to the sample. The most important effect of chloride is that it inhibits the extent of vacancy creation at common operating temperatures of working three-way catalysts, thereby highlighting the unsuitability of chloride-based preparations for such materials. While some chloride can be removed under the low-temperature cycling conditions employed, the extent of this removal is small, and a lower degree of reduction was attained by the chloride sample throughout the series of experiments.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

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: https://hdl.handle.net/11368/1725522
 Attenzione

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

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 27
social impact