Making Rhodium Catalyst for the Ostwald Process

[00:00:00]This is 1 g of roodium metal. And in this video, I'm going to turn it into a catalyst to make nitric acid from ammonia.

[00:00:09]Now, this was actually not really a sane purchase. This actually cost me the entirety of my YouTube revenue and everything everyone donated and I spend it on this.

[00:00:23]Not sure if this was a good idea.

[00:00:25]However, last video or last video I made nitric acid, I determined that you can use platinum. However, it does kind of evaporate or it kind of leaves the catalyst bad and the reaction kind of stops after a few hours. So, I said industrially you use uh 10% roodium and 90% platinum. And that's why I got this rodeium because hopefully this rodeium will not leave as fast. So if this works, this is in my opinion money well spent. But yeah, it is actually the I think it is the most expensive video I've ever done. So I Yeah, let's get started.

[00:01:10]So to get the roodium on the catalyst bed, I need to dissolve it somehow.

[00:01:14]However, this metal is incredibly unreactive and it has a very high melting point. That's the property I want. So, it doesn't just leave the cutter as bad. Rodeium doesn't really react with any acid except sulfuric acid at its boiling point of 337° C. So, I going to have to boil it in that for a while, which will react some of it to roodium sulfate. To this sodium hydroxide is added which will turn the roodium sulfate into roodium hydroxide.

[00:01:45]Roddium hydroxide is insoluble in water though. So to this I'm going to add nitric acid to turn it into the water soluble roodium nitrate that I can soak into the catalyst bed and then decompose to roodium metal by heating it.

[00:02:03]So, I've prepared some sulfuric acid, filled some in this flask, and there's already some in there. God damn it.

[00:02:11]Anyway, I'm going to put the roodium in there. Going to use the fuel colum as a condenser and just set up a reflux and hopefully this will dissolve the roodium.

[00:02:40]Okay, this is running. I did use sulfuric acid to grease the joints. You can't use teflon at this temperature. It will degrade. So, I really hope these joints won't seize up, but we will see.

[00:02:57]It has been running now for the last 4 hours and yeah, the temperature is really high and there's not too much to see, but there is a slight color change and yeah, obviously it's yellow, but it seems to work. So, I'm going to let this run a couple more hours and then see how much rodeium is still left and how much I got dissolved.

[00:03:24]Look at that. Some wonderful red compound. It has been dissolving for basically the entire day. It's I turned it off and I'm going to let this cool down. And then I'm going to get the bead out of there and see how much I actually dissolved. I let this reflux for two days actually. And now there should be enough dissolved. The roodium bead is obviously still in there, but I just want to dissolve a few milligrams off of this. And the next step is to put this in a little bit of distilled water to dilute the sulfuric acid a little bit.

[00:04:01]And then I'm going to start neutralizing this with sodium hydroxide solution. And I'm going to adjust this to a pH of 7.

[00:04:10]And then the roodium sulfate should fall out of solution as roodium hydroxide.

[00:04:34]Okay, I had to move back inside. The weather isn't quite good enough to do chemistry. Kind of sucks. I like it outside more. I think the lighting is better and the audio is also better, but whatever. I'm trying to dissolve the stain from this flask. And this seems to work. It's dissolving. So, that's good.

[00:04:55]This is sodium hydroxide solution.

[00:04:58]And the solution where I poured this into distilled water. There is a little bit of stuff there. And I might have to heat this up to get this to dissolve as well because I definitely want to have everything in solution.

[00:05:14]So I have to see how I can get this into solution, this stuff in there.

[00:05:25]So I combined both of the solution in this beaker and this neutralizes a little bit of the acid, but there's still a lot of acid, so it's still acidic. and all the roodium sulfate should still be dissolved. However, there is a little bit at the bottom and I can't get it to dissolve. I don't know why. I added some water. I boiled it. I stirred it, but it's not dissolving. But the solution itself is pretty clear. So, I'm just going to decant this into a second beaker and just leave this stuff at the bottom for future me to do something with it. So, I'm going to put this in here. And then I'm going to continue neutralizing the acid. And at a pH of around 7, the roodium sulfate in there should precipitate out of solution as roodium hydroxide.

[00:06:23]So, I run out of pH paper, but I bought this pH meter a while ago, so that's maybe even better because I have to continuously check the pH and adjust it to a pH of seven or slightly basics like eight or nine maybe at maximum, but it should be like seven or eight. So, all of the roodium will precipitate out as roodium hydroxide. And there's no roodium or there should be no roodium anymore in solution.

[00:07:15]And here we are with the roodium hydroxide slowly precipitating. I think I'm going to let this stand overnight.

[00:07:23]So, most of it has settled out. There's still some in suspension, but I'm just going to drain the liquid and then fill this up with new water. And repeat this a couple times. This will probably take a couple days if this takes overnight to settle out all the time. But let's see.

[00:07:44]It's working. Oh yeah, it's working.

[00:07:47]Perfect.

[00:08:01]So, while siphoning this, the entire thing just froze because it's just so saturated with sodium sulfate.

[00:08:11]And yeah, let's let's wash this and get the sodium sulfate out of there and separate it from the roodium hydroxide.

[00:08:45]Okay, I'm going back outside. It's a really good weather. It's actually very hot, but let's do some more chemistry.

[00:08:52]So, you might ask yourself, Joan, why don't you just filter this and then wash it with some distilled water? This would be much easier to clean this up. And I didn't want to do this because I thought there will be stuff stuck in the filter paper and then I have losses and stuff.

[00:09:09]However, it does dissolve in acidic solution. So I could just wash it out with acid again. So it's not that big of a deal to filter it. So I'm just going to do that. But I'm not going to use the bulk solution. I actually took the water that was supposedly clear when everything had settled out and put it in here. And there's still stuff settling out over days or weeks or something like that. And I'm just going to slurp up the stuff that's here at the bottom. And that's enough for a catalyst. So I'm going to continue the video with with the stuff that I have in here. So as I said, I'm just going to filter this and then I'm going to add the roodium hydroxide into a test tube. And then I just have to add nitric acid and this will dissolve the roodium hydroxide and I will have a clear solution of roodium nitrate. And this is actually the final product. I will drip this onto some caramic fiber and this will be the catalyst.

[00:10:17]Hey.

[00:10:41]Hey.

[00:10:45]Hey.

[00:10:48]And here's the finished catalyst. Now, I shouldn't end the video. I should at least demonstrate that it works. So, I put together an Oswalt setup somewhat.

[00:10:58]And I'm going to put some ammonia solution in here in this gas wash bottle, and I'll be sucking some air through there with this vacuum pump. And this will this air will pick up some ammonia will react in this quartz tube on the catalyst and this will react to nitrogen monoxide and then to nitrogen dioxide and we will see the color right there. And this way we can see if the reaction works.

[00:11:27]And in a future video I will build a more compact device that will produce nitric acid via the oswalt process. So I don't have to put up the tubing and the glassware every time I want to produce some nitric acid and the catalyst is working. So next time I will put some platinum on this as well. So this was just rodeium and I will like I said we'll build a device that will produce nitric acid.