The technique of cyclic voltammetry was applied in conjunction with on-line catalytic product analysis to investigate the electrochemical promotion of NO reduction by C3H6 in presence of O-2 on Rh catalyst-electrode films on YSZ at temperatures 350-490 degrees C. Cyclic linear potential sweep amperometry under catalytic reaction conditions leads to cyclic non-Faradaic electrochemical modifications in the CO2 formation and NO reduction rates which are compared to those obtained under steady state potentiostatic operation.