Preparation and characterisation of Pt-Ru model electrodes for the direct methanol fuel cell
Preparation and characterisation of Pt-Ru model electrodes for the direct methanol fuel cell
复制标题
直接甲醇燃料电池Pt-Ru模型电极的制备及表征
DOI：
10.1016/s0013-4686(03)00375-x
复制
发表时间：
2003
影响因子：
6.6
通讯作者：
K. Wippermann
中科院分区：
文献类型：
--
作者：
M. Löffler;H. Natter;R. Hempelmann;K. Wippermann
Ru含量为10 ~ 60 at.%的直接甲醇燃料电池用Pt-Ru合金有两种合成方式：一方面，从Pt和Ru粉末的适当混合物开始，通过电弧熔化制备多晶Pt-Ru参比样品。另一方面，将约8 nm的纳米晶Pt-Ru颗粒电化学沉积在玻璃碳盘上的碳/NafionTM层中用于电化学测量。利用X射线线形分析和扫描电子显微镜（EDX）研究了Pt-Ru模型电极的结构特性，如晶格常数、晶粒尺寸和合金成分。通过分析Pt布拉格反射峰随Ru含量增加而发生的连续位移，建立了Pt-Ru合金的校准曲线，该曲线可通过简单的XRD测量确定未知组分样品的Ru含量。铂-钌样品的电化学特征记录准稳态电流-电位曲线方面的铂-钌组合物对甲醇氧化的影响。Pt-Ru催化剂的质量分数为50 at.% Ru对甲醇的电氧化反应最活跃。
Pt–Ru alloys for the direct methanol fuel cell (DMFC) with Ru contents between 10 and 60 at.% were synthesised in two ways: on the one hand, polycrystalline Pt–Ru reference samples were prepared by arc melting starting from appropriate mixtures of Pt and Ru powders. On the other hand, nanocrystalline Pt–Ru particles of about 8 nm were electrochemically deposited in carbon/Nafion™ layers on glassy carbon discs for electrochemical measurements. The structural properties of the Pt–Ru model electrodes, such as lattice constant, grain size and alloy composition, were investigated by X-ray line shape analysis and scanning electron microscopy (EDX). Analysing the continuous peak shift of the Pt Bragg reflexes with increasing Ru content, we established a calibration curve for Pt–Ru alloys which allows to determine the Ru content of samples with unknown composition by simple XRD measurements. The Pt–Ru samples were electrochemically characterised recording quasi-stationary current–potential curves with regard to the influence of the Pt–Ru composition on the methanol oxidation. The Pt–Ru catalyst with 50 at.% Ru turned out to be most active for the methanol electrooxidation.