Electrocatalytic oxidation of formic acid on nano/micro fibers of poly(p-anisdine) modified platinum electrode

• The poly(p-anisidine) was synthesized electrochemically.
• The polymer modified Pt used for the first time for FA oxidation in acid medium.
• It shows an enhanced formic acid oxidation.
• The loading level of the polymer is optimized to give maximum rate of the oxidation process.

Poly(p-anisidine) (PPA) modified platinum (Pt) electrode shows an extraordinary electrocatalytic activity towards formic acid oxidation in acid medium compared to bare Pt electrode. The Pt/PPA is prepared by electropolymerization of the monomer on Pt electrode in salycilate aqueous solution. The PPA has a fiber-like structure with a thread size of nano- to micrometers. The cyclic voltammogram for formic acid electrooxidation on the Pt/PPA shows no peak for the indirect current and the peak current in the backward sweep is almost equal to that in the forward sweep indicating high electrocatalytic activity for FA oxidation compared to the Pt electrode which shows lower tolerance to CO poisoning. The loading level affects both the onset potential and the peak current of formic acid oxidation. Optimization of the loading level shows that a 5 cycles of polymerization (11.8 μg cm−2) is the best loading level of the PPA under the prevailed experimental conditions. The stability of the Pt/PPA towards FA oxidation confirms the higher tolerance to CO poising. SEM images and data analysis demonstrate the facilitated oxidation of FA on the Pt/PPA. Interpretation of the enhancement of FA oxidation on the Pt/PPA electrode is introduced.