Engineering of Amorphous PtOx Interface on Pt/WO3 Nanosheets for Ethanol Oxidation Electrocatalysis

Direct and complete electro-oxidation of ethanol to CO2 is highly desirable for the commercialization of the direct ethanol fuel cells but is challenging. Current electrocatalysts (mainly Pt, Pd) for ethanol oxidation reaction (EOR), unfortunately, still suffer from low CO2 selectivity and rapid performance deterioration. In this study, a new Pt/α-PtOx/WO3 electrocatalyst containing amorphous PtOx structures is successfully synthesized via a facile hydrothermal reaction following Ar atmosphere annealing. The migration of lattice oxygens in the WO3 during the annealing process is confirmed as the mechanism for the formation and manipulation of amorphous interfaces containing PtOx species in the Pt/α-PtOx/WO3 electrocatalyst. The obtained Pt/α-PtOx/WO3 with tunable amorphous PtOx interfaces favors the desorption of poisoning EOR intermediates (such as CO) and high CO2 selectivity. Therefore, the state-of-art of the Pt/α-PtOx/WO3 exhibits excellent EOR activity (2.76 A mg–1), stability (47.99% of the initial activity preserved after 3600 s), and particularly high CO2 selectivity (reached 21.9%, higher than most reported values for Pt or other noble metals based EOR catalysts). This study may provide a new strategy to improve the EOR performance of metal-based catalysts and to rationally design and prepare other high-performing electrocatalysts via engineering the amorphous interfaces.