# What does a catalytic converter consist of?



## Bobplatinum (Sep 22, 2012)

Hello!
I´ve searched on the forum and internet of what a catalytic converter consist of, But i don´t find any good information about that.

So i wonder what does a catalytic converter consist of? 
I know that they contain Pt, Pd and Rh but is there any more metals in catalytics? 
What metals? any other materials?
And what is the ceramic element made of?

/Thanks


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## pimpneightez (Sep 22, 2012)

the outer shell is probably iron, more expensive versions will be made with stainless steel. Just put a magnet to it if it sticks not stainless. The ceramic part is made with(ceramic). And I think they use like an alumina oxide powder on the ceramic to help the pt stick to the ceramic. I could be wrong about some of this and Im sure someone will correct me if I am.


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## rusty (Sep 22, 2012)

pimpneightez said:


> the outer shell is probably iron, more expensive versions will be made with stainless steel. Just put a magnet to it if it sticks not stainless. The ceramic part is made with(ceramic). And I think they use like an alumina oxide powder on the ceramic to help the pt stick to the ceramic. I could be wrong about some of this and Im sure someone will correct me if I am.



409 is a titanium stabilized ferritic stainless steel. Although regarded as a general-purpose chromium stainless steel the primary application for Grade 409 is automotive exhaust systems.

Corrosion Resistance
Grade 409 resists atmospheric and exhaust gas corrosion. A light surface rust will form in most atmospheres; this rust retards further corrosion but makes the surface undesirable for decorative applications. The corrosion resistance is about the same as that of 3CR12 and the 12% chromium martensitic grades such as 410, and inferior to the 17% chromium grade 430.

Heat Resistance
Generally 409 is classified as resistant to scaling in intermittent service up to 815°C and up to 675°C in continuous service, but these temperatures are dependent upon the exact service environment.

Typical applications include:

• Automotive exhaust systems

• Catalytic converters

• Mufflers


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## pimpneightez (Sep 22, 2012)

Thanks for the classification of the type of stainless. I didn't know if it was magnetic or not. Most magnetic stainless steel will be regarded as light iron at the scrap yard unless you have a large quantity of it.


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## Bobplatinum (Sep 22, 2012)

Thanks.
It´s hard to find the answers on these questions!

I read on Wikipedia :http://en.wikipedia.org/wiki/Catalytic_converter

If I have understood right the ceramic element is made of monolith,
and in the ceramic monolith element the active catalysts are the precious metals
platinum, palladium and rhodium ?

The washcoat is used to disperse the materials over the whole area in the catalytic,
And the washcoat is made of aluminium oxide, titanium dioxide or silicone dioxide ?

Also they say that the catalytic contains other metals like Cerium, iron, manganese, nickel and copper.
But what are these metals used for in catalytics ?

/Thanks for answers


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## kurt (Sep 23, 2012)

Bob - you need to go back & re-read the info on wiki about CATs --- it explains it ALL very well

For one thing the PGMs (Platinum Group Metals) are in the wash coat - not in the ceramic monolith

Kurt


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