Pt, Pd, and Rh Pollution From Catalytic Converters

By

BJ, “The Danimal” and Arohme

Catalytic Converters?

• Products of Combustion– Main Emissions:

• CO2

• H2O• N2 -Air is 78% nitrogen gas

– Harmful Emissions- Combustion is never perfect

• CO• Hydrocarbons or Volatile Organic Compounds• Nitrogen Oxides (NO, NO2)

What do Pt, Pd and Rh do?

• Catalyze Reactions– A -Reduction Catalyst – Pt and Rh– B -Oxidation Catalyst – Pt and Pd– C -Honey Comb

Reactions

• Oxygen Catalyst– 2CO + O2 => 2CO2

• Reduction Catalyst– 2NO => N2 + O2 or 2NO2 => N2 + 2O2

How does it get into the environment and cause bad things

to make us want to study it?

• The Palladium and Platinum Ions are binding to Lead within the catalytic converter and the complex is being released as a solid in the exhaust into the environment

What Has Happened?

• Pt and Pd have increased in concentration in sediment samples

After Research,It was found that. . .

• High [Pt] and [Pd] found in dust samples collected on plants growing at edge of high traffic streets and highways

And. . .

• Low [Pt] and [Pd] found in yards of homes in low traffic neighborhoods

Consequences• Concerning increased [Pt]- Various Pt

complexes attack cancer cells by diffusing through the cell membrane, binding to cell DNA, and preventing cell replication

• This has a very negative effect when the use is not localized to an area of attack –ingestion to healthy individuals leads to the DNA attack of healthy cells halting replication (this is no good!)

Consequences Cont.

•Large attack of healthy cells by these replication ceasing complexes causes an early death to the cell and decomposition of the tissue

Detection Methods Available detection method is spectrometric

analysis a number of analysis schemes are

available, the major difference between all the schemes is the sample preparation process.

Interferents are also determined differently in each scheme.

Detection methods (example) Microwave assisted sample digestion and

inductively coupled plasma mass spectrometric determination. (ICp-Ms)

Sample preconcentration with dimethylglyoxime on silica gel before atomic absorption spectrometry.

Regulation The detection methods are very recent

(September 2004). The amounts of Pt, Pd and rhodium

detected are in the trace levels. No formal regulations have been put in

place or cleaning methods have been developed.

Ultimate Fate!! With the new detection methods in place

more amounts of Pt, Pd and rhodium are being detected on highways and tunnels.

If regulations are not put in place soon and clean methods devised, it is only a matter of time before it becomes a major problem.

References Tuit, B. C.; Ravizza, G. E.;Environ. Sci. Technol.

2000, 34, 927-932. Environ. Sci. Technol. 1986, 20, 1058-1060. Analytical Chimica Acta. 2004, 521, 137- 142. Analytical Chimica Acta. 2004, 511, 255-260. http://auto.howstuffworks.com/catalytic-converter.

htm (accessed December 08, 2004.)