Fig. 5: Evidence for the I-PCET mechanism.
From: Proton-coupled electron transfer controls peroxide activation initiated by a solid-water interface
The capture and quantification of the proton was achieved by the implementation of an appropriately performed liquid-phase acid–base titration for (A) CuO/PMS (conditions: [PMS] = 0.1 mM, [CuO] = 2.0 g L–1) and (B) CuO/PDS (conditions: [PDS] = 0.1 mM, [CuO] = 2.0 g L–1). The molar ratio of detected proton (H+) to transferred electron (e–), as determined by titration, is 1:2 for (A), while the ratio is 1:1 for (B). These results indicate that the formation of high-valent metal (–oxo) species is accompanied by the dissociation of the surface-H bond.
