How to Selectively Reduce Fe(III) Without Affecting UO22+?

[Questions_14]

Hi All,

I have been searching the web for days now, trying to find a way to selectively reduce Fe(III) to Fe(II) without reducing the uranium oxide (UO₂²⁺) present, and was hoping someone with more of a chemistry background could give me some advice on what to try/do.


Cheers
Simon

 

[espen180]

Hi, and welcome to PF!

I did some searching on my own, and I think this works.

The reaction UO₂⁺ + e^- → U⁴⁺ + 2O^2- has a standard reduction potential of 0.38 V.

The reaction Fe³⁺ + e^- → Fe²⁺ has a standard reduction potential of 0.771 V.

Since the iron reaction has a higher potential, you can construct a cell where the anode reaction has a potential higher than 0.38 but lower than 0.771, which will then be spontaneous for the iron reaction but not for the uranium reaction.

http://www.webelements.com/uranium/compounds.html

 

[Borek]

The reaction UO₂⁺ + e^- → U⁴⁺ + 2O^2- has a standard reduction potential of 0.38 V.

O₂^- in water solution? That's not the reaction you will observe.

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[espen180]

No, I realize that. Each oxygen ion will immediately deprotinate a water molecule making OH^-.

All I really wanted from the reaction was the reduction potential, but you are right of course, it's not the right picture.

 

[LudusRex]

I understand your frustration with finding a way to selectively reduce Fe(III) without reducing UO22+. This is a common challenge in chemistry, as different elements and compounds have different reduction potentials and reactivity. However, there are a few potential methods you could try to achieve this selective reduction.

One option is to use a reducing agent that specifically targets Fe(III) while leaving UO22+ untouched. For example, you could try using potassium iodide or sodium sulfite, which are known to reduce Fe(III) without affecting UO22+. It may also be helpful to adjust the pH of the solution, as certain pH levels can favor the reduction of Fe(III) over UO22+.

Another approach could be to use a catalyst that can selectively reduce Fe(III). For example, iron sulfide (FeS) has been shown to effectively reduce Fe(III) while leaving UO22+ intact. Additionally, using a specific type of light, such as UV light, can also selectively reduce Fe(III) without affecting UO22+.

It may also be worth considering the use of a chelating agent, which can bind to Fe(III) and prevent it from reacting with other substances. This could help to selectively reduce Fe(III) without affecting UO22+. However, it is important to carefully select a chelating agent that will not also bind to UO22+.

Overall, finding a way to selectively reduce Fe(III) without reducing UO22+ may require some trial and error, as well as careful consideration of the different properties and behaviors of these two elements. I hope these suggestions will be helpful in your research and experimentation. Best of luck!