Self-regeneration of a Pd-perovskite catalyst for automotive emissions control

Y. Nishihata (), J. Mizuki, T. Akao, H. Tanaka, M. Uenishi, M. Kimura, T. Okamoto and N. Hamada
Additional contact information
Y. Nishihata: Japan Atomic Energy Research Institute
J. Mizuki: Japan Atomic Energy Research Institute
T. Akao: Japan Atomic Energy Research Institute
H. Tanaka: Technical Center, Daihatsu Motor Co. Ltd
M. Uenishi: Technical Center, Daihatsu Motor Co. Ltd
M. Kimura: Toyota Central R&D Laboratories Inc.
T. Okamoto: Toyota Central R&D Laboratories Inc.
N. Hamada: Tokyo University of Science

Nature, 2002, vol. 418, issue 6894, 164-167

Abstract: Abstract Catalytic converters are widely used to reduce the amounts of nitrogen oxides, carbon monoxide and unburned hydrocarbons in automotive emissions. The catalysts are finely divided precious-metal particles dispersed on a solid support. During vehicle use, the converter is exposed to heat, which causes the metal particles to agglomerate and grow, and their overall surface area to decrease. As a result, catalyst activity deteriorates. The problem has been exacerbated in recent years by the trend to install catalytic converters closer to the engine, which ensures immediate activation of the catalyst on engine start-up, but also places demanding requirements on the catalyst's heat resistance. Conventional catalyst systems thus incorporate a sufficient excess of precious metal to guarantee continuous catalytic activity for vehicle use over 50,000 miles (80,000 km). Here we use X-ray diffraction and absorption to show that LaFe0.57Co0.38Pd0.05O3, one of the perovskite-based catalysts investigated1,2,3,4 for catalytic converter applications since the early 1970s, retains its high metal dispersion owing to structural responses to the fluctuations in exhaust-gas composition that occur in state-of-the-art petrol engines5. We find that as the catalyst is cycled between oxidative and reductive atmospheres typically encountered in exhaust gas, palladium (Pd) reversibly moves into and out of the perovskite lattice. This movement appears to suppress the growth of metallic Pd particles, and hence explains the retention of high catalyst activity during long-term use and ageing.

Date: 2002
References: Add references at CitEc
Citations: View citations in EconPapers (8)

Downloads: (external link)
https://www.nature.com/articles/nature00893 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:418:y:2002:i:6894:d:10.1038_nature00893

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature00893

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().