电催化剂及其对甲酸氧化的电催化性能

采用氨水调节的微波多元醇法合成了Pd/C和Pd2Pt/C催化剂,并使用透射电镜(TEM)和X-射线衍射(XRD)对催化剂的微观结构和形貌进行了表征.结果显示,在微波合成的电催化剂中Pd和Pd2Pt纳米粒子具有均匀的粒径,并高度分散在XC-72纳米碳载体上,Pd和Pd2Pt纳米粒子的平均粒径分别为54 和49 nm. 电化学测试结果显示,甲酸在Pd/C催化剂上氧化的起始电位和峰电位大大低于Pt/C催化剂,这是由于甲酸在Pd/C和Pt/C催化剂上不同的氧化途径引起的.结果还显示,甲酸在Pd2Pt/C催化剂和Pd/C催化剂上氧化的起始电位相同,而且在024和080 V有两个分别对应于甲酸在Pd和Pt催化剂的氧化, 说明微波合成的Pd/C和Pd2Pt/C催化剂对甲酸的氧化具有良好的电催化性能.

Microwave synthesis of Pd/C and Pd2Pt/C electrocatalysts for fomic acid electrooxidation

Pd/C and Pd2Pt/C electrocatalysts were synthesized by ammonia mediated microwave polyol process, and their microstructure and morphology were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was found that the as-synthesized Pd and Pd2Pt nanoparticles were homogeneous in size and were highly dispersed on the surface of XC-72 carbon. The diameters of Pd and Pd2Pt were 54 and 51 nm, respectively. The electrochemical measurements showed that the onset potential and peak potential of fomic acid oxidation on Pd/C catalyst were much lower than those on Pt/C catalyst due to the reason that reaction pathways of fomic acid oxidation on Pd/C was different from that on Pt/C catalysts. The Pd2Pt/C catalyst displayed a low onset potential for the fomic oxidation, which was equal to that on Pd/C, and two current peaks of fomic oxidation at 022 and 089 V were attributed to the fomic acid oxidation on Pd and Pt catalysts. The facts indicated that the microwave synthesized Pd/C and Pd2Pt/C electrocatalysts exhibited better electrocatalystic performances than Pt/C.