<p>Electrolysis of ethanol to produce green hydrogen, with less electrical energy than for water electrolysis, is potentially an attractive sustainable energy technology. However, more efficient anode catalysts are required, and the production of acetic acid and acetaldehyde by-products must be considered. PtRhM (M = Sn, Ni, Ru) catalysts can potentially combine the high activities of PtM catalysts with the enhanced selectivity of PtRh for breaking the ethanol C–C bond, which increases hydrogen production. The purpose of this work was to compare these catalysts in a proton exchange membrane (PEM) cell and measure stoichiometries and product distributions. The results show that although Sn, Ni, and Ru all enhance the activity of PtRh at low potentials for cyclic voltammetry in H₂SO₄(aq), only Ru had a significant effect in the PEM cell. However, Ni enhanced selectivity for breaking the C–C bond, while Ru and Sn both decreased selectivity. Consequently, PtRhNi appears to be most suitable for production of hydrogen from ethanol oxidation, because it provides the optimum balance between the electrical energy required, current density, and hydrogen/ethanol ratio (higher stoichiometry).</p> Graphical Abstract <p></p>