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 ◽  
...  
2021 ◽  
Author(s):  
Ershuai Liu ◽  
Qingying Jia ◽  
Jun Yang ◽  
Kai Sun ◽  
Li Jiao ◽  
...  

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.


Pramana ◽  
1979 ◽  
Vol 12 (4) ◽  
pp. 317-329 ◽  
Author(s):  
W H Madhusudan ◽  
Sheelavathi Kollali ◽  
P R Sarode ◽  
M S Hegde ◽  
P Ganguly ◽  
...  

2016 ◽  
Vol 18 (25) ◽  
pp. 16930-16940 ◽  
Author(s):  
Christina A. Cama ◽  
Christopher J. Pelliccione ◽  
Alexander B. Brady ◽  
Jing Li ◽  
Eric A. Stach ◽  
...  

The first XAS study of (de)lithiation of CuFe2O4 showed iron can be reoxidized while Cu0 remains in its reduced form.


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