Pt-Au bimetallic catalysts have been fabricated on glassy carbon electrode (GCE) substrate by the potentiostatic method. Catalyst samples have been characterized by scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDX) and electrochemical methods. SEM results reveal that the samples are composed of near-spherical particles, and the surfaces of particles are rough. The results of cyclic voltammetry and chronoamperometry show that the addition of Au into bimetallic catalysts is beneficial to the electro-catalytic oxidation of formic acid and the anti-poisoning ability of platinum for formic oxidation is enhanced. Furthermore, the formic acid oxidation mechanism on these bimetallic catalysts has also been elucidated using an electrochemical impedance spectroscopy technique. Meanwhile, the different amount of Au in bimetallic catalysts has been studied for formic electrooxidation, and the results show that Pt₁Au_1.803 catalyst has the highest catalytic activity for formic acid electro-oxidation.

Key words: formic oxidation, bimetallic catalyst, electrodeposition, electrocatalysis