Altered electrochemistry at graphene-or alumina-modified electrodes: Catalysis vs electrocatalysis in multistep electrode processes

The voltammetric behavior of glassy carbon electrodes modified with either submonolayer quantities of alumina or graphene is examined with respect to the two-electron, two-proton reaction of catechol (1,2-dihydroxybenzene) in aqueous solution. While the voltammetric behavior superficially hints at a change of electron transfer rate, an alternative explanation in terms of the changed thermodynamics of the intermediate species is advanced and rationalized.