Electrocatalytic water oxidation beginning with the cobalt polyoxometalate [Co4(H2O)2(PW9O34)2]10-: identification of heterogeneous CoOx as the dominant catalyst.

TLDR: Electrochemical, kinetic, UV-vis, SEM, EDX, and other data provide four main lines of compelling evidence that, under the conditions used herein, the dominant WOC is actually heterogeneous CoO(x) and not homogeneous [Co(4)(H(2)O)(2)(PW(9)O(34))(2)](10-).

Abstract: The question of “what is the true catalyst?” when beginning with the cobalt polyoxometalate (POM) [Co4(H2O)2(PW9O34)2]10– in electrochemical water oxidation catalysis is examined in pH 8.0 sodium phosphate buffer at a glassy carbon electrode. Is [Co4(H2O)2(PW9O34)2]10– a true water oxidation catalyst (WOC), or just a precatalyst? Electrochemical, kinetic, UV–vis, SEM, EDX, and other data provide four main lines of compelling evidence that, under the conditions used herein, the dominant WOC is actually heterogeneous CoOx and not homogeneous [Co4(H2O)2(PW9O34)2]10–.