DMFC的PtRu-NdO_x/C催化剂合成及性能

Study on preparation and characteristic of PtRu-NdOx /C catalyst for the direct methanol fuel cell

以NdOx作为助催化剂,采用浸渍还原法合成了不同原子比例的PtRu-NdOx/C催化剂。首先研究了不同还原温度对PtRu/C催化剂的电催化性能的影响。X射线衍射光谱法(XRD)和循环伏安测试结果表明:当还原温度为90℃时,合成出的催化剂粒度最小,对甲醇电氧化的催化性能也最好。其次,通过能量散射X射线谱(EDX)、XRD、透射电子显微镜法(TEM)和循环伏安法、计时电流法等测试手段,研究了不同n(Pt)∶n(Ru)∶n(Nd)原子比例对PtRu-NdOx/C催化剂性能的影响。实验结果表明:n(Pt)∶n(Ru)∶n(Nd)原子比为3∶3∶1时,合成出的催化剂电催化性能较好;而且Pt与Ru以合金形式存在,而Nd的氧化物则以无定形态存在,催化剂粒子分布均匀,平均粒径在2nm左右。

The PtRu-NdOx/C catalysts were prepared by impregnation method using NdOx as co-catalyst. The effects of reduction temperature on the electrochemical catalytic activity of PtRu/C catalysts were investigated. The results of XRD and cyclic voltammetry show that when the reduction temperature is 90℃,the PtRu/C catalyst has smaller particle size and higher performance than the catalysts prepared at 80 ℃ and 100℃. The effects of atom ratio of Pt ： Ru ： Nd were investigated by EDX, XRD, TEM. cyclic voltammetry and chronoamperometric measurements. The results demonstrate that when the atom ratio of Pt ： Ru ; Nd is 3 ; 3 ; 1, PtRu-NdOx/C catalyst appears preferable catalytic activity towards methanol oxidation. Pt and Ru had come into being alloy, while the Nd oxides existed in amorphous form. The catalysts are highly dispersed and their average particle size is about 2 nm.