Electrocatalysts for the oxidation of ethanol in proton exchange membrane fuel cells, electrolysis cells, and sensors

The potential for direct ethanol fuel cells (DEFCs) to provide sustainable, widely accessible power has driven development electrocatalysts for the ethanol oxidation reaction (EOR) over several decades. However, low power output, low efficiencies, and the production of acetic acid and acetaldehyde byproducts has caused progress to stall. Consequently, interest in this area is transitioning to electrolysis of ethanol to produce green hydrogen and commodity chemicals. Concurrently, applications of DEFC as breath alcohol sensors in breathalyzers are increasing, and this has become an established commercial market for EOR catalysts. Progress in the development of these technologies has been hampered by the limited number of catalysts that have been evaluated in proton exchange membrane cells, the paucity of data on product distributions, and limited gas-phase-sensing studies.