R.G. Freitas

Ethanol electrooxidation using Ti/(RuO2)(x) Pt(1-x) electrodes prepared by the polymeric precursor method

This work describes a detailed study of the ethanol electrooxidation on Ti/(RuO2)(x)Pt(1-x) electrodes using several compositions prepared by the polymeric precursor method. The results obtained using cyclic voltammetry and chronoamperometry showed that the best composition of Ti/(RuO2)(x)Pt(1-x) electrodes for CO and ethanol oxidation processes is Ti/(RuO2)0.50Pt0.50. On this electrode composition the onset of CO and the ethanol oxidation occurred at 380 mV and 220 mV more negative than on Ti/Pt, respectively. Besides, there was an increase of 2.5-fold in the current density for ethanol electrooxidation under constant potential polarization. The Ti/(RuO2)0.50Pt0.50 electrodes produced lower amount of acetic acid compared to Ti/Pt and polycrystalline Pt electrodes using in situ HPLC spectrometric analysis. Also, a non common product from ethanol oxidation could be observed on higher RuO2 loads: ethyl acetate. Finally, the impedance data showed that Ti/(RuO2)0.50Pt0.50 electrode composition had the smallest charge transfer resistance for ethanol oxidation among those compositions investigated