A bi-functional cathode structure for alkaline-acid direct ethanol fuel cells

An issue associated with the use of hydrogen peroxide as the oxidant in the so-called alkaline-acid direct ethanol fuel cell (AA-DEFC) is the problem of H₂O₂ decomposition, which causes a significant decrease in the cathode potential. The present work addresses this issue by developing a bi-functional cathode structure that is composed of the nickel-chromium (Ni-Cr) foam (functioning as the diffusion layer) with a highly dispersed gold particles (functioning as the catalyst layer) deposited onto the skeleton of the foam. This integrated cathode structure allows not only a reduction in H₂O₂ decomposition, but also an enhancement in the species transport in the cathode of the AA-DEFC. The fuel cell performance characterization shows that the use of the bi-functional cathode structure in the AA-DEFC enables the peak power density to be increased to 200 mW cm⁻² from 135 mW cm⁻² resulting from the use of the conventional cathode.