Sciencemadness Discussion Board

Alkali Hydrides; No Catalyst, No High Temperatures

Meltonium - 22-12-2016 at 07:33

I just read this article

http://phys.org/news/2016-12-solvent-free-catalyst-free-alka...

in it the researchers claim to have made high-grade alkali metal hydrides using a ball mill! They say this reaction requires no high temperatures and no catalyst.

In addition, they claim, "While increasing the pressure of the hydrogen gas accelerated the hydrogenation process, the research found that the process will work with high-capacity industrial milling operations with minimal modifications." Meaning you can do it at home!

If anybody has a ball mill and is willing to try this, I would definitely enjoy hearing it.


Bert - 22-12-2016 at 07:48




Quote:
If anybody has a ball mill and is willing to try this, I would definitely enjoy hearing it.


Yes, I imagine anyone in the neighborhood might hear it if amateur chemists start filling ball mills with alkali metals and H2...

Call me a cynic, but seriously. Handling the feed stocks alone, OR the end products without a fire/explosion is difficult enough for an amateur. Adding a H2 feed system to a mechanism with a revolving reaction chamber and running the device full of Li, K or Na is going to be one of those things that industry can do, but is "a challenge" for small scale home applications.

I know there are people here who could do it. But would they?





[Edited on 22-12-2016 by Bert]

Fulmen - 22-12-2016 at 08:40

Quote: Originally posted by Bert  
I know there are people here who could do it. But would they?


C'mon, I know you want to. Go on...

Chemetix - 22-12-2016 at 14:44

Yup! i'm mad enough!

Dan Vizine - 23-12-2016 at 09:05

The "high temperature" isn't that high. The reaction proceeds well enough at 200 C. Use of an inert reaction medium is more of an advantage than a disadvantage.

It would be far simpler to build an apparatus to do the reaction at 200 C than to successfully inert the mill and recover an unprotected solid.

This seems to be suited to a manufacturer, not a home lab. Sure, I could do this, but I wouldn't.

zed - 26-12-2016 at 17:24

Well.... If you are a clever tool monkey, you could build such a machine.

But, the older Paar reactor method isn't bad.

Not too hard to produce NaH or NaAlH4. And from there, you can get to many other hydrides.

There are some other references here on Science Madness, try the search engine.

What we are really waiting for, is a low-tech Borohydride Synthesis.
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OK, that was yesterday. Here is one of the patents we discussed in the past. http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sec...

The bugaboo, was the need for using TriethylAluminum. Hard to handle, and not an easy make.
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A later patent application, suggests that TriethylAluminum can be avoided when using an alternate solvent like Diglyme. https://www.google.com/patents/CA1238767A?cl=en

These conditions can be achieved with a standard stirred Paar pressure reactor.



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