The kinetics of the electrocatalytic hydrogenation of ethylene at positive potentials has been studied over polytetrafluoroethylene‐bonded, porous platinum black electrodes in perchloric acid electrolyte. Pore diffusion was generally not a significant factor except at low concentrations of reactants. Steady‐state kinetic parameters and deuterium exchange results suggest that surface reaction of hydrogen with ethyl radicals is rate limiting. A mechanistic model is proposed and examined in terms of Temkin adsorption of hydrogen atoms in the low potential region (<0.18V). Strong Langmuir adsorption of ethylene appears to take place for all mechanisms considered. The energy production of the electrogenerative reactor is favored by high electrolyte concentration, high alkene partial pressure, elevated temperatures, and increased catalytic loading.