Direct Alcohol Fuel Cells: A Comparative Review of Acidic and Alkaline Systems
- Authors: Berretti E.; Osmieri L.; Baglio V.; Miller H.A.; Filippi J.; Vizza F.; Santamaria M.; Specchia S.; Santoro C.; Lavacchi A.
- Publication year: 2023
- Type: Review essay (rassegna critica)
- OA Link: http://hdl.handle.net/10447/608433
Abstract
In the last 20 years, direct alcohol fuel cells (DAFCs) have been the subject of tremendous research efforts for the potential application as on-demand power sources. Two leading technologies respectively based on proton exchange membranes (PEMs) and anion exchange membranes (AEMs) have emerged: the first one operating in an acidic environment and conducting protons; the second one operating in alkaline electrolytes and conducting hydroxyl ions. In this review, we present an analysis of the state-of-the-art acidic and alkaline DAFCs fed with methanol and ethanol with the purpose to support a comparative analysis of acidic and alkaline systems, which is missing in the current literature. A special focus is placed on the effect of the reaction stoichiometry in acidic and alkaline systems. Particularly, we point out that, in alkaline systems, OH- participates stoichiometrically to reactions, and that alcohol oxidation products are anions. This aspect must be considered when designing the fuel and when making an energy evaluation from a whole system perspective.