PtRu合金薄膜结构及其催化性能

Structure and Catalytic Properties of PtRu Alloy Thin-film

采用离子束溅射技术(IBS)在碳纤维布基底上制备PtRu/C合金薄膜作为燃料电池电极催化材料.应用XPS、XRD、GIXD、AFM等分析手段研究了PtRu薄膜表面的成分、化学状态、表面形貌以及PtRu薄膜的表层、次表层和体相的结构.结果表明,在双束离子沉积过程中,由于溅射产生的Pt+和Ru+之间的相互作用,使薄膜表面的化学状态和薄膜表层(15-40nm范围内)结构发生了变化,并影响PtRu薄膜的催化性能.当xPt/xRu=0.64时,PtRu薄膜出现Ru固溶体在表层富集,并在表层诱发形成Pt39Ru61非晶相.

A PtRu alloy thin-film used for catalytic electrodes of fuel cells was fabricated by ion beam sputtering （IBS）. The structure, surface layer structure, chemical composition, surface chemical state, and morphology of the PtRu alloy thin-film were characterized using X-ray diffraction （XRD）, grazing incidence X-ray diffraction （GIXD）, X-ray photoelectron spectroscopy （XPS）, and atomic force microscopy （AFM）. It was shown that the surface chemical state and structure in the top layer （from 1540 nm） of PtRu alloy thin-film were changed due to the strong interaction between Pt^＋ and Ru^＋ during the ion beam sputtering deposition process, which also affected the catalytic activity of the PtRu alloy thin-film. In particular, when the atomic ratio of xPt/xRu was 0.64, enrichment of the Ru solid solution and amorphous phase Pt39Ru61 were observed on the surface layer of PtRu alloy thin-film.