Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-12-01T10:44:50.698Z Has data issue: false hasContentIssue false
  • English
  • Français

Transmission Electron Microscopy Studies of Pd Encapsulation by Ceria-Zirconia Oxides

Published online by Cambridge University Press:  02 July 2020

J. C. Jiang ,
X. Q. Pan ,
G. W. Graham ,
R. W. McCabe  and
J. Schwank
J. C. Jiang
Affiliation:
Department of Materials Science & Engineering, University of Michigan, Ann Arbor, MI48109
X. Q. Pan
Affiliation:
Department of Materials Science & Engineering, University of Michigan, Ann Arbor, MI48109
G. W. Graham
Affiliation:
Chemical and Physical Sciences Laboratory, Ford Motor Company, MD3179/SRL., Dearborn, P.O. Box 2053, MI48121
R. W. McCabe
Affiliation:
Chemical and Physical Sciences Laboratory, Ford Motor Company, MD3179/SRL., Dearborn, P.O. Box 2053, MI48121
J. Schwank
Affiliation:
Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI48109
Get access

Extract

High-temperature catalysts containing Pd supported on high-surface area ceria-zirconia are optimum materials for fuel economy when automotive engines operate under high speed or load conditions. A prerequisite for developing such thermally stable catalysts is to gain a good understanding of the thermal deactivation modes contributing to the aging and degradation of catalysts in harsh thermal environments. It was discovered by X-ray diffraction that upon hightemperature aging, Pd may sinter into large (about 10 nm diameter) particles and become encapsulated in the ceria-zirconia. To confirm this conclusion, a prototype high-temperature catalyst containing Pd supported on high-surface area ceria-zirconia, aged at temperature above 1100 °C is studied by transmission electron microscopy (TEM).

The ceria-zirconia supported Pd (0.25 wt%) catalyst was aged at 1105 °C and calcined at 700 °C for 2 h. For TEM sample preparations, first of all, a large-size aggregate with diameter about 1 mm was selected and sandwiched between by two pieces of silicon crystal.

Type
Nanophase and Amorphous Materials
Information
Microscopy and Microanalysis , Volume 4 , Issue S2: Proceedings: Microscopy & Microanalysis '98, Microscopy Society of America 56th Annual Meeting, Microbeam Analysis Society 32nd Annual Meeting, Atlanta, Georgia July 12-16, 1998 , July 1998 , pp. 724 - 725
Copyright
Copyright © Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Graham, G. W., Jen, H. -W., Chun, W., and MaCabe, R. W., Catal. Lett. 44 (1997) 185CrossRefGoogle Scholar