Polyaniline-Decorated Carbon as Composite Carrier for Improving PtNi Catalyst Durability

Polyaniline (PANI) was synthesized on carbon cloth with a diffusion layer by an electrochemical technique and characterized by Fourier-transform infrared spectrometry, x-ray photoelectron spectroscopy, and scanning electron microscopy. PANI polymerized by a potentiostatic and a pulse potential method showed different morphologies. The former showed a granular shape and the latter a reticular structure. The reticular PANI was more suitable as a catalyst carrier based on the results of a cyclic voltammetry test. A PtNi catalyst electrodeposited on the reticular PANI-decorated carbon cloth (PtNi/PANI(PP)-C) had a smaller particle size and a homogeneous distribution. PtNi/PANI(PP)-C exhibited a higher electrochemical active surface area and better electrocatalytic activity according to the cyclic voltammetry and single cell polarization tests. Linear sweep voltammetry measurements indicated that PtNi/PANI(PP)-C showed excellent oxidation-reduction reaction activity through a four-electron transfer pathway. The results of an accelerated durability test showed that the performance degradation of PtNi/PANI(PP)-C was slower than that of PtNi/C. The reticular PANI-decorated carbon carrier improved the electrochemical activity and durability of the catalyst.