A new kind of ternary Pt(Cu)/TiO 2 catalyst was prepared by photodeposition of Cu on TiO 2 powder support and subsequent galvanic deposition of Pt from a solution of K 2PtCl 6 salt. For its characterization energy-dispersive spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction were applied. The electrochemical and photoelectrochemical behavior of the platinized Cu/TiO 2 catalyst with respect to methanol oxidation reaction (MOR) was evaluated by cycling potentiometric and chronoamperometric electrochemical measurements in darkness and under UV light irradiation. The electrocatalytic activity of the Pt(Cu)/TiO 2 catalyst towards MOR was evaluated and compared to that of a commercial Pt/C catalyst. The inherent catalytic activity demonstrated by Pt(Cu)/TiO 2 electrode was higher than the Pt/C catalyst and the specific mass activity was comparable. At low overpotential the current at the Pt(Cu)/TiO 2 catalyst is further enhanced under UV light illumination. The improved behavior of Pt(Cu)/TiO 2 is associated with effective dispersion and utilization of Pt due to several circumstances. It is prepared by galvanic displacement of photodeposited Cu and galvanic deposition on photoreduced Ti(III) sites. Due to this, Pt-Cu interaction, as well as the mutual potentiating action of Pt and TiO 2 eases the oxidative detachment of CO poisonous intermediates from Pt (in the dark) and enhance TiO 2 photogenerated electron-hole separation efficiency (under illumination).
- Galvanic replacement
- Titanium dioxide