Electrooxidation of ethanol on a nickel oxyhydroxide-modified electrode

In the past decades, the direct methanol fuel cell (DMFC) has drawn attention for its simple construction with reduced dimensions and high-energy efficiency. Progress has been made in this field [1-3]. However, the intrinsic DMFC disadvantage is the toxicity of methanol. Therefore, researchers have looked for other small alcohol molecules as alternative fuels. Ethanol has emerged as the first choice because of its relative non-toxicity and low volatility together with a higher energy density compared to methanol (8.01 KWh kg-1 versus 6.09 KWh kg-1). Other important considerations for choosing ethanol are its low price, natural availability, renewability, high power density, zero green-house contribution to the atmosphere and its transportability. Among the published reports on proton exchange membrane fuel cells (PEMFC) with alcohols as fuel, the direct ethanol fuel cell (DEFC) seems promising, especially for the application in devices like electric vehicles, mobile telephones and laptops. Pt and Pt alloy electrodes provide simple electrocatalytic surface for oxidation of ethanol. However, the complete oxidation of ethanol in DEFC remains the crux of the matter, because, unlike the case of DMFC, it is necessary to break the C-C bond of ethanol at low temperatures.