Use of X-ray Absorption Spectroscopy To Study Reaction Mechanisms at Metal Oxide—Water Interfaces

1999 ◽  
pp. 14-36 ◽  
Author(s):  
Gordon E. Brown ◽  
George A. Parks ◽  
John R. Bargar ◽  
Steven N. Towle
Keyword(s):  
Metal Oxide ◽  
Absorption Spectroscopy ◽  
Reaction Mechanisms ◽  
X Ray ◽  
X Ray Absorption

scholarly journals Unveiling the Degradation Nature of Pt/NbOx/C Catalysts for Oxygen Reduction Reaction via in situ X-ray Absorption Spectroscopy

2021 ◽  
Author(s):  
Ershuai Liu ◽  
Qingying Jia ◽  
Jun Yang ◽  
Kai Sun ◽  
Li Jiao ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Absorption Spectroscopy ◽  
Reduction Reaction ◽  
X Ray ◽  
Orr Activity ◽  
X Ray Absorption

Among various metal nanoparticles supported on metal oxide (MMO) catalysts, the Pt/NbOx/C system has promising oxygen reduction reaction (ORR) activity as cathode for proton exchange membrane fuel cells (PEMFCs). Herein, we study a series of Pt/NbOx/C catalysts with tunable structural and electronic properties via physical vapor deposition and unravel the nature of metal and metal oxide interaction (MMOI) by characterizing this system under reactive conditions. By conducting in situ X-ray absorption spectroscopy (XAS) experiments, we demonstrate the Pt preferably interacts with O but not Nb in the Pt/NbOx/C system and such Pt-O interaction benefits the ORR activity via electronic effect rather than strain effect. We also provide clear evidence for the formation of metallic Nb phase at the early stage of PEMFC operation and identify severe particle growth of Pt after long-term PEMFC operation. These findings deepen our understanding of the degradation mechanism of MMO catalysts during long-term PEMFC operation.

Chemical effects at metal/oxide interfaces studied by x-ray-absorption spectroscopy

2001 ◽  
Vol 64 (21) ◽  
Author(s):  
T. J. Regan ◽  
H. Ohldag ◽  
C. Stamm ◽  
F. Nolting ◽  
J. Lüning ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Absorption Spectroscopy ◽  
Oxide Interfaces ◽  
X Ray ◽  
Chemical Effects ◽  
X Ray Absorption
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