A Novel Way of Sampling Particles Containing Platinum Group Elements from Automobile Catalysts

Abstract

A new sampling system was developed in order to be applied directly at the exhaust pipe of vehicles combined with an exhaust gas analyzer during the standard New European Driving Cycle (NEDC). In that way a quantitative sampling of Pt, Pd, and Rh (Platinum Group Elements, PGEs) in particle form on filters and gas monitoring could be achieved simultaneously, applying the sampling system on a variety of vehicles of different age and engine capacity. The samples were examined by SEM-EDX for morphological and qualitative analysis of the particles. By using an appropriate digestion procedure and the analytical techniques of ICP-MS and GFAAS, concentrations were found in the range of 0.35–87 ng/km for Pt, 3.3–437 ng/km for Pd, and 0.9–72 ng/km for Rh. Furthermore the investigation showed that fresh catalysts as well as engines with larger capacity emitted higher amounts of PGEs in comparison to older catalysts and smaller capacity engines. According to the results of this research the palladium emissions were dominant in comparison to the platinum ones. This way of sampling might prove advantageous in testing new technology catalysts through their PGEs emission.

Keywords:

• Aerosol particles
• Automobile catalyst
• Palladium
• Platinum
• Rhodium

Acknowledgments

This paper is part of a special issue organized by Dr. Nikolaos Thomaidis and Dr. Antony C. Calokerinos from research presented at the Aegean Analytical Chemistry Days Conference in Lesvos, Greece on 29 September–3 October 2010.

The authors would like to thank Mr. Apostolos Spanos of the Department of Exhaust Gases Control of the Hellenic Ministry of Transport & Communications and Dr. Klaus M. Ochsenkühn of the NCSR “Dimokritos,” Athens, Greece for their cooperation.

This research was undertaken with funds from the Basic Research Committee Program “PEVE 2008” (NTUA).

Notes

*These data were not used in the calculation of the mean values, as they were assumed to be a nugget effect.