Sciencemadness Discussion Board

platinum catalyst

jester1068 - 8-10-2006 at 03:10

Does anyone know what the feasability of using auto catalytic converter honeycomb in a hydrogen bomb for the catalyst is? The catalytic converter is a ceramic substrate with alumina sprayed on it to increase the surface area. The platinum, palladium, and/or rhodium is suspended in the alumina and applied at the same time. I am new to the p2p thing and has never really looked into the mechanics of the bomb route-as it seeems outdated with all the new easy methods that seem to be evolving daily. Isn't Pd one of the best all around metal catalyst for alot of proccesses and less efficient catalysts are used because of the availability of platinum metals? Maybe it could be utilized in a home vapor phase reaction over the catalyst. People could make small reactors based on the designs from the industrial production of many popular products- it seems that alot of these compounds that are discussed, are commercially created in vapor phase reactors using the cheapest reagents and usually in continuous batch. With a good metal fab shop, one could make small versions of industrial mfg. plants.

not_important - 8-10-2006 at 09:16

Quote:
Originally posted by jester1068
... Isn't Pd one of the best all around metal catalyst for alot of proccesses and less efficient catalysts are used because of the availability of platinum metals?


You mean 'because of the cost of platinum metals'?
Quote:
Maybe it could be utilized in a home vapor phase reaction over the catalyst. People could make small reactors based on the designs from the industrial production of many popular products- it seems that alot of these compounds that are discussed, are commercially created in vapor phase reactors using the cheapest reagents and usually in continuous batch. With a good metal fab shop, one could make small versions of industrial mfg. plants.


There are some possible problems with that idea. Industrial processes can be difficult to scale down. Many depend on precise control of temperature, flow rate, contacts time, rations of reactants, and so on. These can prove hard to replicate on a small scale.

Another aspect of ibndustrial processes is that they may have fairly low conversion rates, depending on separation of products and unreated raw materials, with the unreacted portion being recycled. The spearation is down using fractionating towers with a large number of theoretical plates, higher than you are going to get with a standard lab fractionation column. In some things size does count, a fractionating tower 10s of meters tall can do much better than the 400 mm packed glass tube in your lab.


I'm not sure if automobile exhaust catalytic converters are the best choice for reduction use. They are targeted at oxidation reaction while minimising the amount of nitrogen oxides formed, and run at higher temperatures than reductions normally do. They also have had several differing formulations, exactly how much of which metals has changed. It's not going to be cookbook, either you need a detailed describtion of what the converter was like for all makes and models of autos, or you will need to determine what your particular converter is good for, under what conditions.


One area that is starting to become important is the microreactors. These often depend on wall effects that are not seen in standard industrial processes, or even semi-micro lab work. The design of the microreactors allows good control of heat, large scale production would have arrays of microreactors. Some of these could be built by DIY, however they are fairly - methods and reactions are still in development.