I am trying to find a good material to use as a coating with a very high overpotential for OER reaction
Given its stability and interesting properties, maybe alumina may be a good and inexpensive option.
I have limitation in Using Alumina as it is not stable in concentrated basic solution.
What are the other options in your mind? and How I can find better options? what consideration I need to take?
I believe the considerations you need to take are your limitations according to the synthesis technique you want use, and post processing. The stability of metal oxides is typically very high, but some of them can have non-stoichiometry phases (or easily accomodate oxygen vacancies), or simply have lower stoichiometry states.
In this way, for instance, I would not suggest Nb2O5 since it can be reduced to lower stoichiometry phases, and therefore diffuse the oxygen to your material... The same for MnO2, V2O5, iron oxide...
Is SiO2 an option? How about TiO2?
That is right.
My plan in using ALD process to coat an oxide on my powder which I am gonna use as cathode material. So, there is no definite limitation in terms of synthesizing method. SiO2 would also not stable in concentrated basic solution.
Is there a very famous groups of oxides for suppression of oxygen evolution ? how I can find them and also their criteria?
I do not know about an organized list of oxides set by their ability of oxygen evolution.
I would look for "rust", i.e. metal oxides but with the above considerations of lower stoichiometries.
I do not know if lattice mismatch could be a problem for you or not...
If being an oxide is really a requirement, I'm not recalling anything more that I could say. If it's not, the metal nitrates may be interesting.
I wish you luck!
Thanks Claudio,
But I can tell there is no serious concern about lattice mismatch.
On the other side, YES, I can also consider other kind of components, even metals and as you said nitrates.
Remember that, people are usually trying to find a better catalyst for easier oxygen evolution. But I am walking in the opposite direction, the more suppressing Oxygen evolution reaction, the more I am interested in.
My colleagues from Dnipropetrovsk (Velichenko A.B. et al) studied PbO2 electrodes in depth. I think it will help!
http://www.sciencedirect.com/science/article/pii/S1572665714000502
I vote for titania (TiO2). It can be also reduced to Ti(+3) and Ti(+2) and can be easily re-oxidized.
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