I've an electrochemical cell with an electrolyte of copper methane sulfonate, manganese methane sulfonate and 3-4M methanesulfonic acid.

I'm looking for a membrane or coating that will be permeable for cu2+ and Mn2+, but hinder passage of Mn3+.

The system would benefit from a coating on the positive carbon electrode (Mn2+/Mn3+ redox) that could be formed in situ by reaction or electrochemically.

Any suggestions?

Thanks,

Filip Ponsaerts