Transmission electron microscopy studies of the nanoscale structure and chemistry of Pt50Ru50 electrocatalysts.
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.
Stroud
Rhonda M
RM
Surface Modification Branch, Naval Research Laboratory, Washington, DC 20375, USA.
Long
Jeffrey W
JW
Swider-Lyons
Karen E
KE
Rolison
Debra R
DR
D000497:Alloys / Q000737:chemistry*; D002384:Catalysis; D004577:Electron Probe Microanalysis; D013058:Mass Spectrometry / Q000379:methods; D000432:Methanol / Q000378:metabolism; D008854:Microscopy, Electron / Q000295:instrumentation / Q000379:methods*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D012428:Ruthenium / Q000737:chemistry*
D000497:Alloys; D010984:Platinum; D012428:Ruthenium; D000432:Methanol