Modification of Nafion™ membrane to reduce methanol crossover via self-assembled Pd nanoparticles

Abstract

Positive-ion charged Pd nanoparticles were synthesized and anchored to –SO3− clusters on Nafion™ membrane surface by means of selective force between –SO3− clusters and charged particles, namely, electrostatic self-assembly of the membrane. The Pd loading of self-assembled membrane was about 1.73 μg/cm2. Methanol crossover of the Nafion™ membranes was suppressed after the assembled procedure. The methanol crossover current was reduced by as much as eight orders of magnitude compared to pure Nafion™ membrane while there was no reduction in the proton conductivity of the membrane. Methanol permeating across the resulting Nafion™ membranes was 1.3×10−15 mol cm−2 s−1, comparing with the value of pure Nafion™ membranes (self-assembled for 0 h) of 1.4×10−7 mol cm−2 s−1. The results demonstrate the promises of the application of such Pd-PDDA nanoparticle self-assembled Nafion™ membrane in DMFC.