Comparative Assessment of Alkaline and Acidic Electrochemical Reforming of Bio-ethanol for Hydrogen and Value-Added Chemicals Production

Electrochemical reforming of biomass-derived oxygenates offers an industrially viable route to co-produce high-added-value chemicals and green hydrogen at lower voltages than conventional water electrolysis. Over the past five years, more than 200 studies have demonstrated rapid advances, with both proton exchange membrane (PEM) and anion exchange membrane (AEM) systems achieving industrially relevant current densities (1 A cm-2) at cell voltages even below 1 V. However, the electrolyte pH has a profound influence on the process through reaction pathways, catalyst and membrane stability, and even on overall reaction stoichiometry. In this opinion, we provide a critical comparison of the often-overlooked differences between acidic and alkaline technologies, highlighting their distinct thermodynamic, kinetic, mass-balance, and energetics trade-offs, to define the research priorities in the path toward the scale-up and deployment of high added value chemicals.