Chapter 4. Electrochemical Reforming of Alcohols

Abstract

With the emergence of the hydrogen economy, an intense search for economical sources of hydrogen is mandatory. In this sense, the electrochemical reforming of alcohols in proton or alkaline exchange membrane electrolysis cells has emerged as a solid alternative for hydrogen production in contrast to water electrolysis. The main attraction of this technology is the lower theoretical energy demand ascribed to the alcohol vs. water electro-oxidation. Methanol, ethanol, and, recently, glycerol and ethylene glycol are the most extensively used alcohols because they are obtained from environmentally sustainable processes. Electrochemical reforming of alcohols faces similar challenges as direct alcohol fuel cells. The development of active electrocatalysts for alcohol electro-oxidation is crucial for the success of electrochemical reforming. Thus, this chapter is devoted to the state-of-the-art electrocatalysts for alcohol oxidation and their application in electroreformers, both in acidic medium, in which Pt-based materials appear to be the most active, and alkaline medium, in which a wider spectrum of metals has been proposed successfully. In this sense, Pd-based electrocatalysts are considered competitive in comparison to Pt. Although significant advances have been achieved, there is still room for improvements, with the incentive of making this technology more competitive.