Preparation of a Novel Composite Membrane and PtRu/Hollow Carbon Sphere (HCS) Anode Catalyst for Alkaline Direct Methanol Fuel Cell (ADMFC)

Abstract

This work demonstrated the synthesis process of the anion-exchange nanocomposite membrane based on Poly(vinyl alcohol (PVA) and Quaternary ammonium silica precursor (QASP), which was synthesized by using Glycidytrimethyl ammonium chloride (GTMAC) and 3-Aminopropyl trimethoxysilane (AMPTS). The suitable amount of functional SiO2 fillers was added into the PVA composite polymer membrane to reduce the methanol permeability and also improve the thermal and mechanical properties. A novel and high activity PtRu/Hollow carbon sphere (HCS) was synthesized to use as a catalyst in the anode for methanol oxidation. It was found that this as-prepared PtRu/HCS shows excellent electrochemical activity, as compared with PtRu black. The characteristic properties were examined by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), micro-Raman and FTIR spectroscopies, scanning electron microscopy (SEM), and AC impedance method. It was observed that the maximum ionic conductivity of anion-exchange composite polymer membrane is around 5.12×10-2 S cm-1 at room temperature. It was observed that the highest peak power density of alkaline direct methanol fuel cell (ADMFC) with a 4M KOH + 2M CH3OH fuel was around 70 mW cm-2 at 70oC. The methanol permeability is around 10-6∼10-7 cm2 s-1. The results demonstrate that the PVA/QASP/SiO2 composite membranes exhibit a good candidate for application to ADMFC.