Effect of cations on the electro-oxidation of alcohols and polyols on Pt: Activity, selectivity, and mechanistic insights

Understanding the role of cations in the electro-oxidation of alcohols and polyols (EOAP) on Pt electrodes is essential for optimizing electrocatalytic processes in energy conversion and chemical production. This review explores how cations modulate activity, selectivity, and dynamic behavior during the EOAP. Larger cations, such as K⁺, enhance reaction rates and facilitate C–C bond cleavage, whereas smaller cations like Li⁺ promote CO_ad oxidation and the formation of inactive Pt oxides. The interplay between cations, adsorbed intermediates, and the electrode surface is analysed using complementary electrochemical and in situ spectroscopic techniques, covering hypotheses proposed to explain these observations. Despite progress, fundamental questions remain regarding the microscopic origins of cation effects, including the relative stabilities of key intermediates, how these stabilities influence their formation and oxidation, and ultimately how they govern the deactivation of Pt surfaces via the formation of inactive Pt oxides.