Papers by Keyword: Ethanol Oxidation

Abstract: The tungsten modified Pd-based nanocatalyst for ethanol oxidation in alkaline media was prepared by an ethylene glycol reduction method, and the catalytic performances of the prepared catalysts were evaluated. The results show that the addition of tungsten improved the dispersion of metal nanoparticles on the support surface and thus increased the current density of Pd-based catalyst for ethanol electrooxidation. In addition, it was found that in the tungsten modified Pd-based catalyst, tungsten interacted with palladium, leading to a low onset potential and a decreased active energy for ethanol oxidation. On the other hand, it was also observed that the addition of tungsten improved the poison resistance of Pd-based catalysts for ethanol oxidation.

Abstract: An efficient method for functionalizing carbon nanotubes (CNTs) is reported, which combined HF corrosion with sulfuric acid and nitric acid for further oxidation. The X-ray diffraction and transmission electron microscopy are employed to investigate the physic-properties of the prepared catalysts. Cyclic voltammetry and chronoamperometry methods are used to study the performance of the prepared catalysts. CNTs further treated with H2SO4 and HNO3 mixed solutions with the volume ratio of 1 to 3, heating at 100 oC for 2 h, used as catalysts supports exhibit significantly improved performance towards ethanol oxidation in alkaline solutions in comparison with other decorated CNTs. The reason could be attributed to the oxygen-contain functional groups on CNTs surface can efficiently improve the interaction between CNTs and metallic particles in catalysts.

Abstract: Pt-Sn/WC(O)/C catalysts with different Pt/Sn molar ratio have been prepared by microwave-assisted reduction method. In the synthesis, PtSn alloy was supported on WC(O)/C which was synthesized by the temperature-programmed carburization after the pretreatment of AMT precursor. XRD result shows that Pt particles are reduced successfully. Compared to the reflections of Sn-free sample, the diffraction peaks of PtSn alloy catalysts shift to lower angle slightly. The electrocatalytic activities towards ethanol oxidation reaction were investigated using cyclic voltammetry and chronoamperometry techniques in acid media. The sample of Pt3Sn2/WC(O)/C presents the highest peak current density (332.2 mA/mg-Pt) and stability.

Abstract: Carbon-supported PtRuRh nanoparticles, PtRuRh/C, were prepared by an impregnation method as a new anode catalyst with a high activity for ethanol oxidation in a direct ethanol fuel cell (DEFC). PtRuRh (2:1:1)/C, of which the metal loading and the metal particle diameter was 40 wt% and 6.7 nm, respectively, with the metal composition of 2:1:1 for Pt:Ru:Rh, showed a higher oxidation current at a certain electrode potential compared to that of PtRu (1:1)/C and Pt/C prepared in a similar manner. The DEFC with PtRuRh (2:1:1)/C as the anode catalyst generated about a 1.5 times and 3 times higher electric power compared to that of PtRu (1:1)/C and Pt/C, respectively, with 2M ethanol.

Abstract: Pd electrocatalysts supported on TiO2 nanotubes (TNTs) were prepared and used for the oxidation of ethanol in alkaline media. The morphology and structure of the TNTs and the Pd-TNTs/Ti catalyst were characterized by field emission scanning electron microscopy (FESEM). The FESEM results showed that the nanotube structure could be obtained after Ti anodized for 40 min at 20 V under 25 °C, and the nanotube length increased with anodizing time. TNTs/Ti40, TNTs/Ti50 and TNTs/Ti90 templates were prepared with Ti anodized for 40 min, 50 min and 90 min respectively. The composite catalysts activities were measured by cyclic voltammetry (CV), impedance spectroscopy and chronoamperometry. The results indicated that the Pd-TNTs/Ti50 catalyst had higher catalytic activity for ethanol oxidation compared with Pd-TNTs/Ti40 and Pd-TNTs/Ti90 catalysts.