Experimental
Preparation Pt/SnO2 by the sol–gel technique
The precursor of the tin(IV) oxide was tin (IV) acetate. To 48 cm3 of isopropanol, and 8 cm3of methanol 1.6 g of the tin (IV) acetate was added and immersed in an ultrasonic bath at 323 K until tin (IV) acetate dissolved. Increasing amounts of Н2PtCl6 · 6H2O solution were added to the tin acetate alcohol solution: 1.35 cm3, 2.7 cm3 and 5.4 cm3 respectively, corresponding to 28.12 mg, 56.24 mg and 112.55 mg of Pt to obtain samples containing 4.1 wt % (series A), 8.2 wt % (series B) and 16.4 wt % (series C) of Pt. After Н2PtCl6 · 6H2O dosing, the systems were dispersed in an ultrasonic bath at 323 K for 12 hours.
Physicochemical characteristics
The phase identification and the influence of the thermal treatment on SnO2 phase was performed using an X-ray diffraction (XRD) powder diffractometer (Philips, PW 1050) using CuKα lamp radiation and Ni filter. X-ray spectra were recorded in the angular range of 5–80 [2theta]. Imaging the surface was performed with SEM electron microscopy (Zeiss EVO 40) and TEM (JOEL JEM 1200 EX).
The thermal analysis of SnO2 gel thermal analysis was performed using a TA Instruments gravimetric analyser (TA50) under nitrogen atmosphere, 20 cm3/min, at heat rate of 20 K/min and under air atmosphere 20 cm3/min, at heat rate of 20 K/min.
Surface studies was carried out using an FT-IR spectrometer (Bruker, TENSOR 27) from ATR accessory (SPECAC). Measurement resolution was 4 cm−1.
The cyclic voltammetry (CV) experiment was performed in a two-electrode cell of Swagelok type with the application of ECLAB V10.12 VMP model 0.3 potentiostat/galvanostat by Bio-Logic, in the range of potential from −0.5 to 1.0 V. The scan rate of 0.05 mVs−1 was applied.
The catalyst powders were suspended in solution of PVdF-HFP in acetone with graphite and applied onto a stainless steel electrode. The cell’s configuration was: steel-Pt/SnO2 | separator | steel. The electrolyte contained 1 mol/dm3 H2SO4 and 0.5 mol/dm3 CH3OH.
Competing interests