Sciencemadness Discussion Board

Cerium trichloride from Cerium dioxide

Triflic Acid - 27-6-2021 at 16:50

I know that this has been discussed many times before here, but does anyone with firsthand experience have a good prep starting from glass grinding grade cerium dioxide? Or maybe some route to make a soluble cerium salt from cerium 4 sulfate?

Or actually, should I start from ferrocerium how should I separate iron chloride from cerium chloride?

[Edited on 28-6-2021 by Triflic Acid]

Bedlasky - 27-6-2021 at 21:36

http://www.sciencemadness.org/talk/viewthread.php?tid=65869

https://www.sciencemadness.org/whisper/viewthread.php?tid=24...

Lion850 - 27-6-2021 at 22:06

The below is my report some time ago on making cerium sulphate from CeO2. Once you have cerium sulphate you can probably react that with baking soda or sodium or potassium carbonate solution to get cerium carbonate as a ppt, or with sodium hydroxide to get cerium hydroxide. The carbonate or hydroxide can then be your start point for other cerium salts. The original post also have some photos:

https://www.sciencemadness.org/whisper/viewthread.php?tid=15...

You should also read this:

http://www.sciencemadness.org/talk/viewthread.php?tid=155289...


Report on making cerium sulfate

After a few experiments spread out over weeks attempting to make different cerium salts from cerium oxide CeO2 I eventually realised that with what I had at hand reacting the CeO2 with hot concentrated sulphuric acid was the easiest.

One of my initial attempts was to react CeO2 with a slight excess of 98% H2SO4 in a crucible in a sand bath at around 200 C. The CeO2 dissolved easily forming a yellow-red wet thick liquid. I continued to heat this in the sand bath maintaining around 200 C. Eventually there was no more acid fumes coming off but it was still liquid. Upon cooling this solidified into a dry mass with off-yellow color. I broke this up and into a coarse powder and transferred it to a vial.

Reading up on atomistry http://cerium.atomistry.com/ceric_sulphate.html
I assume that what I got was the basic cerium sulfate 3CeO2.4SO3

The second time I dissolved CeO2 in 98% H2SO4 at lower temperature, the sand temperature was kept at around 140 C. A slightly larger excess of acid was used. Again the CeO2 dissolved easily and formed a very wet orange paste. This paste was put in a desiccator over NaOH and under vacuum for 48 hours. I then had a wet yellow paste but in the bottom of the crucible was a hard reddish layer.

The red layer was removed and was found to be easily soluble in water. This is probably a hydrate of ceric sulfate.

The wet yellow paste went back into the desiccator but it did not dry any further and maintained a strong acid smell. Following what is mentioned in Atomistry (link above) I transferred the yellow paste into a beaker with glacial acetic acid and stirred until it was a fine yellow suspended powder. This solution was then filtered.

The yellow remainder was washed twice more with glacial acetic acid in the funnel. it was then scratched off the filter paper and into a crucible. It was slowly turning orange as it was exposed to the moisture in the air during this process.

The crucible with the yellow (now slight orange) powder was transferred to a desiccator over 98% sulphuric acid as drying agent and under vacuum. The color became more yellow over time. After 5 days it was removed as a yellow dry mass, this was broken into smaller pieces and quickly transferred to a vial. It had a very faint vinegar smell from the acetic acid washing. If left in moist air it becomes wet and turns orange-brown. I assume this yellow product is anhydrous ceric sulfate Ce(SO4)2.

Photos of both products below.

Both products dissolves easily in water, and then gives a ppt of cerium hydroxide when treated with ammonium solution. This cerium hydroxide, in turn, easily dissolves in hydrochloric acid or nitric acid for making other cerium compounds, which was the initial object.







Triflic Acid - 28-6-2021 at 19:59

On another note, maybe adding ferrocerium to GAA will give just Ce(OAc)3 without touching the iron. Then I could take this, make the hydroxide and work my way up to the chloride?