Electrocatalytic Oxidation of HCOOH on Pt-based Anodes

We compared the electrochemical characteristics of electrodeposited platinum, bismuth-modified platinum (PtBim), and ruthenium-modified platinum (PtRum) electrodes in the electrocatalytic oxidation of con- centrated formic acid. The methods of choice were using cyclic voltammetry (CV), impedance spectroscopy (EIS), and electrochemical quartz crystal microbalance (EQCM) techniques. In CV experiments, in compar- ison with Pt and PtRum, the PtBim electrode showed superior catalytic activity in the oxidation of HCOOH over the potential range 0.0∼0.4 V by hindering the adsorption of CO and favoring the dehydrogenation of formic acid. The PtRum electrode showed better performance than the Pt electrode, owing to the ability of Ru to catalyze the formation of OH. The EIS data showed that the reaction resistance increased with the increase of the formic acid concentration on the Pt electrode; on the PtBim and PtRum electrodes, the reaction resistance decreased with the increase of the formic acid concentration.