Due to the great importance of automotive exhaust gas treatment, the catalytic activity was investigated in selective catalytic reduction of NO by propene on Pt films - with controlled microstructure - deposited on YSZ (8 mol% Y2O3-doped ZrO2) by electrostatic spray deposition. This technique requires low Pt loadings in order to reduce costs and also to achieve high Pt particles dispersion with good reproducibility. This kind of electrochemical catalysts was found to be effective for NO reduction by propene in the presence of oxygen. A dense Pt film was found to be the most suitable. Furthermore, we have demonstrated that these electrochemical catalysts can implement the concept of electrochemical promotion of catalysis (EPOC). (C) 2008 Elsevier B.V. All rights reserved.