Ostwald process

[seba]

I want to understand how the catalyst works in the Ostwald process, i mean why can platinum be exchanged for copper. And can i use any metal?

 

A nice video of it: http://www.carlton.paschools.pa.sk.ca/chemical/mtom/contents/chapter3/fritzhaber_2.htm

[RyanJ]

According too the information I have a copper catalyst is not used, according to the information I have the components of the catalyst are platinum with with a small amount of rhodium.

 

I can find no mention of copper anywhere in my books...

 

Cheers,

 

Ryan Jones

[seba]

According too the information I have a copper catalyst is not used' date=' according to the information I have the components of the catalyst are platinum with with a small amount of rhodium.

 

I can find no mention of copper anywhere in my books...

 

Cheers,

 

Ryan Jones[/quote']

 

Yes indeed, but in the experiment (link in my previous post) they've used copper and it still worked.

[RyanJ]

Yes indeed, but in the experiment (link in my previous post) they've used copper and it still worked.

 

Ah, I see. Its probably because copper and platinum have simmilar catalytic properties

 

Cheers,

 

Ryan Jones

[seba]

Ah' date=' I see. Its probably because copper and platinum have simmilar catalytic properties

 

Cheers,

 

Ryan Jones[/quote']

 

Can i receive a more detailed explanation?

I've once read a long time ago (i don't think if i remember correctly.) that platinum's catalytic proprieties are to accumulate on the surface elementary O/H. Is this correct?

[aj47]

I would imagine platinum works as heterogenous catalyst in which case only a few types of transition metals could be used.

 

Basically heterogenous catalyst, like platinum for this reaction, will have active sites where the reagents can be absorbed onto. This increases the rate of the reaction by either breaking up the reagents into more reactive fragments, holding the reagent molecules in the right configuration for a more favourable collision or weakening bonds to lower activation energy.

 

Only a limited number of transition metals can be used for a partiular reaction, as each metal will absorb reactant molecules at different strengths.

For example if a metal like tungsten is used in this reaction, the molecules will be absorbed far too strongly and will not release the products fast enough to increase the overall rate of reaction. Conversley if a catalyst like silver is used, the reactants will be absorbed too weakly and molecules will not stay long enough on an active site to react.

 

I would imagine copper is not as effective as platimum but I doubt it would make much difference in a lab, only on an industrial scale. Plus its a hell of a lot cheaper too.

[dttom]

I have a related question, could I know how we determine how strong the reagent adsorbs to different transition metal?