Highly Efficient Fuel Cell Electrodes from Few-Layer Graphene Sheets and Electrochemically Deposited Palladium Nanoparticles

TL;DR

This paper presents a novel, highly efficient ethanol fuel cell electrode made from few-layer graphene sheets with electrochemically deposited palladium nanoparticles, achieving exceptional activity, stability, and low catalyst loading.

Contribution

The study introduces a new electrochemical deposition process using high voltages to control palladium nanoparticle distribution on graphene electrodes, enhancing fuel cell performance.

Findings

High catalyst activity of 7977 mA/(mg Pd) at low loadings

Maximum current density of 106 mA/cm² at high loadings

Excellent stability and poisoning resistance

Abstract

An extremely efficient ethanol fuel cell electrode is produced by combining the large surface area of vertically oriented and highly conductive few-layer graphene sheets with electrochemically deposited palladium nanoparticles. The electrodes show an extraordinary high catalyst activity of up to 7977 mA/(mg Pd) at low catalyst loadings of 0.64 $\mu$g/cm$^2$ and a very high current density of up to 106 mA/cm$^2$ at high catalyst loadings of 83 $\mu$g/cm$^2$. Moreover, the low onset potentials combined with a good poisoning resistance and long-term stability make these electrodes highly suitable for real applications. These features are achieved by using a newly developed electrochemical catalyst deposition process exploiting high voltages of up to 3.5 kV. This technique allows controlling the catalyst amount ranging from a homogeneous widespread distribution of small ($\leq$ 10 nm) palladium nanoparticles to rather dense layers of particles, while every catalyst particle has electrical contact to the graphene electrode.