摘要
用铁作掺杂元素,通过液相均相沉淀 气/固高温还原两段反应方法制备了碳载Pt Fe合金催化剂,比较了3种不同Fe含量催化剂的电催化性能。采用X射线衍射和X光电子能谱技术研究了Fe掺杂对Pt/C催化剂晶体结构及表面元素存在形态的影响。结果显示:Pt Fe/C催化剂比单一Pt/C催化剂有更小的晶格参数,其中Fe元素可能的存在形态应为与铂结合的合金态,但不排除表面存在部分氧化态。单电池放电稳定性实验表明:在200mA·cm-2电流密度下放电时电池电压基本稳定,其中Pt与Fe摩尔比为1∶1时电极催化效果相应较好,但大电流密度放电时电池电压下降比单一Pt/C催化剂电极的快,这说明Fe的加入能提高催化剂的电催化性能,但阴极表面氧原子浓度较大时,Fe可能发生氧化而使得电极稳定性受到影响。
Carbon-supported Pt-Fe alloy catalysts were prepared by two-step reaction containing liquid depositing and gas-solid reducing. The electrocatalytic characteristics of the catalysts with different contents of Fe were compared. The effects of Fe on the crystal structure and the state of elements in Pt-Fe/C were investigated by XRD and XPS techniques. The results show that Pt-Fe/C catalyst has smaller crystal lattice parameter than Pt/C catalyst and the potential state of Fe in it should be alloy state integrated with Pt, but a portion of Fe in the catalyst surface exists as ferric oxides as well. It is also found that the catalyst in which molar ratio of Pt to Fe is 1∶1 is provided with preferable catalytic characteristic, but the electrode stability is not much satisfied when single cell using Pt-Fe/C as cathode is discharged at larger current density.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2004年第7期1156-1161,共6页
The Chinese Journal of Nonferrous Metals
