Elsevier

Journal of Catalysis

Volume 189, Issue 2, 25 January 2000, Pages 326-338
Journal of Catalysis

Regular Article
Redox and Chemisorptive Properties of Ex-Chloride and Ex-Nitrate Rh/Ce0.6Zr0.4O2 Catalysts: 1. Effect of Low-Temperature Redox Cycling

https://doi.org/10.1006/jcat.1999.2712Get rights and content

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.

References (33)

  • J. Kašpar et al.

    Catal. Today

    (1999)
  • T. Murota et al.

    J. Alloys Compd.

    (1993)
  • P. Fornasiero et al.

    J. Catal.

    (1996)
  • P. Fornasiero et al.

    J. Catal.

    (1999)
  • P. Vidmar et al.

    J. Catal.

    (1997)
  • P. Fornasiero et al.

    J. Catal.

    (1995)
  • F.M.Z. Zotin et al.

    Appl. Catal. A Gen.

    (1993)
  • P. Fornasiero et al.

    J. Catal.

    (2000)
  • R. Di Monte et al.

    J. Alloys Compd.

    (1998)
  • P. Fornasiero et al.

    Appl. Catal. B Environ.

    (1999)
  • G.S. Zafiris et al.

    J. Catal.

    (1993)
  • S. Bernal et al.

    J. Catal.

    (1992)
  • P. Fornasiero et al.

    J. Catal.

    (1997)
  • F. Fajardie et al.

    J. Catal.

    (1998)
  • D.I. Kondarides et al.

    J. Catal.

    (1998)
  • S. Salasc et al.

    Catal. Today

    (1999)
  • Cited by (31)

    • Influence of a synthesis method and a support nature on physicochemical and catalytic properties of supported rhodium catalysts for the partial oxidation of hydrocarbons. I. Chloride series

      2021, Molecular Catalysis
      Citation Excerpt :

      In particular, Rh-containing catalysts were found to be more selective and active in the partial oxidation of hydrocarbons, both gaseous and liquid [1,2]. At that, it is important to take into account the influence of the precursor of the active component on the properties of the catalyst [3]. The most commonly used support for such catalysts is alumina [4,5], which possesses all the properties necessary for the optimal support [6] and provides good dispersion of the metal and high resistance to sintering and poisoning with sulfur [4].

    • Methanol steam reforming behavior of copper impregnated over CeO<inf>2</inf>-ZrO<inf>2</inf> derived from a surfactant assisted coprecipitation route

      2015, International Journal of Hydrogen Energy
      Citation Excerpt :

      A common feature for all the materials is the appearance of a low temperature H2 consumption peak between 70 and 210 °C that is not observed for the bare supports. This peak is clearly due to the addition of copper that not only is reduced to Cu0, but can also promote CeO2 reduction through a spillover mechanism widely reported in literature for ceria supported metal catalysts [43,44]. At increasing CeO2 loading the peak tends to split into three features that are distinguished clearly on Cu10CZ80: the maxima have been related to the reduction of amorphous CuO clusters, bulk CuO interacting with surface ceria and CuO crystallites [45].

    • Investigation on properties of a novel ceria-zirconia-praseodymia solid solution and its application in Pd-only three-way catalyst for gasoline engine emission control

      2011, Fuel
      Citation Excerpt :

      CeO2 as a component of automotive catalysts has a number of the essential drawbacks: the stability is not sufficient for hard exhaust conditions, and its surface area drastically decreases under a high temperature, leading to the catalyst deactivation [18]. It has been reported that the thermal stability, oxygen storage capacity, redox properties and catalytic activity of ceria–zirconia solid solution can be strongly enhanced in comparison with pure CeO2 [19–22]. Therefore, in modern TWC formulations, ceria–zirconia solid solution is included instead of CeO2 to cater for the OSC requirement [8].

    View all citing articles on Scopus
    1

    To whom correspondence should be addressed. E-mail: [email protected]. Fax: +39 040 6763903.

    View full text