adsorb both H and OH optimally. In this work, single-crystal voltammetry and microkinetic
modeling show that an OH-mediated mechanism is not viable on Pt (110). Only a direct
Volmer step can explain observed kinetic trends with OH adsorption strength in KOH and
LiOH electrolytes. Instead, OH behaves as a rapidly equilibrated spectator species that
decreases available surface sites and slows hydrogen kinetics. These results identify kinetic …