Pt50Ru50电催化剂纳米级结构与化学性质的透射电子显微镜研究。

Transmission electron microscopy studies of the nanoscale structure and chemistry of Pt50Ru50 electrocatalysts.

作者信息

Stroud Rhonda M, Long Jeffrey W, Swider-Lyons Karen E, Rolison Debra R

机构信息

Surface Modification Branch, Naval Research Laboratory, Washington, DC 20375, USA.

出版信息

Microsc Microanal. 2002 Feb;8(1):50-7. doi: 10.1017/S1431927602010097.

DOI:10.1017/S1431927602010097

PMID:12533204

Abstract

The structural and chemical heterogeneity of 2.5-nm Pt50Ru50 electrocatalysts was studied by transmission electron microscopy using selected area diffraction, lattice imaging, electron-energy loss spectroscopy, and energy-dispersive X-ray spectroscopy. The catalysts with the highest methanol oxidation activities exhibit oxidation-induced phase separation on the nanoscale to from Pt-rich metal embedded in Ru-rich hydrous and anhydrous oxide. Reduction of the oxide-on metal samples produces a true bimetallic face-centered cubic Pt50Ru50 alloy, with 275 times lower oxidation activity.

摘要

通过使用选区衍射、晶格成像、电子能量损失谱和能量色散X射线光谱的透射电子显微镜研究了2.5纳米Pt50Ru50电催化剂的结构和化学异质性。具有最高甲醇氧化活性的催化剂在纳米尺度上表现出氧化诱导的相分离，形成嵌入富Ru含水和无水氧化物中的富Pt金属。对金属上的氧化物样品进行还原会产生一种真正的面心立方双金属Pt50Ru50合金，其氧化活性降低275倍。