Why The Carbon Supported Ptfes Catalysts Were Prepared By A Modified Polyol Method

1386 Words Nov 29th, 2016 6 Pages
The carbon supported PtFeS catalysts were prepared by a modified polyol method. In brief, 0.3 g carbon (Ketjen-black heat-treated at 2250 °C, SE = 160 m2 g-1) was dispersed in 135 g ethylene glycol. 5.993 g of 8 wt% H2PtCl6 (Umicore; Pt content, 39.8 wt%), 1.874 g of 8 wt% FeCl3. 6H2O (Sigma-Aldrich), and 0.352 g of 8 wt% (NH2)2SC (Sigma-Aldrich) previously mixed in ethylene glycol were added to the dispersion. The pH of the stirred reaction mixture was adjusted to ∼11 using 1 M NaOH dissolved in ethylene glycol. Then, 2.095 g of 50 wt% H2NaPO2.H2O and 1.57 g of 20 wt% hydrazine were added to the reaction mixture. The resulting mixtures were reduced in a microwave reactor at 250 °C for ∼1 h. The reduced resulting product was washed with deionized water 4 times and dried in a freeze dryer. The as-prepared sample was treated with 1 M nitric acid solution to dissolve Fe and S atom on the surface of PtFeS catalyst at room temperature (RT) for 1 h and then washed 4 times with deionized water and dried in a freeze dryer again, thereby obtaining a 38 wt% PtFeS/C catalyst. For the comparison, 37 wt% Pt/C was prepared following the literature procedure [22].

2.2 Characterization
X-ray diffraction (XRD) patterns were obtained using a Philips X’pert Pro X-ray diffractometer equipped with a Cu-Kα source at 40 kV and 40 mA. The crystalline sizes of Pt alloy particles on the carbon supports were calculated from the XRD patterns by using Scherrer’s equation [23]. TEM images and the…

Related Documents