Comparison of Catalytic Activity for Methanol Electrooxidation Between Pt/PPy/CNT and Pt/C

Abstract

This work explored the catalytic effect of Pt in multi-wall carbon nanotube and poly-pyrrole conductive polymer electrocatalysts (Pt/PPy/MWCNT). A home-made Pt/PPy/MWCNT catalyst was first evaluated by comparing its electrochemical active surface area (ESA) with E-Tek commercial catalysts by cyclic voltammetry in <TEX>$H_2SO_4$</TEX> solution. Then, the methanol oxidation currents of Pt/PPy/MWCNT and the hydrogen peaks in <TEX>$H_2SO_4$</TEX> solution were serially measured with microporous electrode. This provided the current density of methanol oxidation based on the ESA, allowing a quantitative comparison of catalytic activity. The current densities were also measured for Pt/C catalysts of E-Tek and Tanaka Precious Metal Co. The current densities for the different catalysts were similar, implying that catalytic activity depended directly on the ESA rather than charge transfer or electronic conductivity.