应用溶胶法制备出5种不同原子数比的Pt-Ru-Ni/C样品,用X射线衍射光谱(XRD)、X光电子能谱(XPS)表征催化剂的晶相结构、表面组成及价态形式。在碱性条件下,采用循环伏安法测试催化剂电催化氧化甲醇的活性。结果表明,掺杂Ni可提高Pt-Ru/C催化活性,Ni在Pt-Ru-Ni合金中的原子数分数与其催化活性呈火山形关系,其中Pt5-Ru4-Ni0.7/C的活性最高,在1.0 mol/L NaOH溶液+1.0 mol/L CH3OH溶液中峰电流密度达842.2 mA/mg,甲醇起始氧化电位比Pt5-Ru5/C的低约0.16 V,在甲醇浓度较低时,甲醇反应级数为0.58级。
The catalysts of Pt-Ru-Ni/C with different atom ratio were prepared by colloidal method.The surface composition and crystal pattern of nano-particle supported by carbon black were characterized by X-ray diffraction and energy dispersive X-ray spectroscopy.The catalyst activity in different methanol and NaOH concentration electrolytes was measured by cyclic voltammetry. The results show that,the performance of Pt-Ru/C for methanol electro-oxidation was improved mark-edly by doping with Ni,and the relation between the activity of Pt-Ru-Ni/C and Ni atom ratio in alloy nano particles appeared volcanic.The Pt5Ru4Ni0.7/C gave the best performance among the five catalysts with different Ni atom ratio,and the peak current density on Pt5Ru4-Ni0.7/C reached 842.2 mA/mg and the onset potential of methanol electro-oxidation was 0.16 V lower than that of Pt5-Ru5/C in 1.0 mol/L NaOH+1.0 mol/L CH3OH.In the electrolyte with low methanol concentration,the methanol reaction order was 0.58.