甲醇在不同结构氧化钨-Pt/C催化剂上的电催化氧化行为

Compared Study of Catalytic Activity for Methanol Oxidation on Different Pt-WO_3/C Electrodes

采用水热法合成2种氧化钨(WO3)纳米材料,并利用XRD和电子探针显微分析仪(EPMA)进行了表征。利用循环伏安法研究了Pt-WO3/C电极对甲醇氧化的电催化活性。结果表明,Pt-WO3/C催化剂对甲醇氧化的电催化活性优于Pt/C催化剂,且氧化钨质量分数为20%的Pt-氧化钨/C催化效果最好。与青铜相氧化钨掺杂的Pt/C电极比较,掺杂焦绿石型氧化钨的Pt/C电极催化性能有很大提高,这是由于焦绿石型氧化钨表面具有较多OHads。质量分数20%的Pt-焦绿石型氧化钨/C在0.5 mol/LCH3OH+1 mol/L H2SO4溶液中对甲醇氧化的峰电流密度达到87.2×10-3 A/cm2。

Tungsten oxide-based nano-materials with two different crystal structures were prepared by hydrothermal method and characterized by X-ray diffraction（XRD） and electron probe micro analyzer（EPMA）,respectively.The electrocatalytic activity for methanol oxidation on Pt-WO3/C electrode was studied by cyclic voltammetry.The results indicate that the electrocatalytic activity of Pt-WO3/C is much higher than that of Pt/C catalyst.For various amount of WO3,the catalyst with 20% mass fraction of WO3 has the best electrocatalytic activity.The electrocatalytic activity of the pyrochlore type tungsten oxide doped Pt/C electrode is higher than that of the tungsten bronze doped electrode,which is likely due to the strong attractions of OHads on the surface of pyrochlore type tungsten oxide.The current density of the pyrochlore type tungsten oxide doped Pt/C electrode for electro-oxidation of methanol is 87.2×10-3 A/cm2 in 0.5 mol/L CH3OH＋1 mol/L H2SO4 solution.