[gdlchmst]

In a pH 7 Na-phosphate buffer, at what oxidative potential would a glassy carbon electrode start to corrode? Suppose bulk electrolysis conditions. Thanks in advance for any response.

[Mark Imisides]

GC is a pretty robust electrode material, but nonetheless it will certainly decompose at extreme potentials (normally you actually see little black bits flaking off).

I don't have much experience with phosphate electrolytes, but I'd imagine you'd start to see it happening at around 1.3-1.4V vs Ag/AgCl. You can't see it on a voltammogram of course, as it's buried under the oxygen wave.