Mechanism of ep additive-metal interaction

1983 ◽  
Vol 16 (6) ◽  
pp. 291-296 ◽  
Author(s):  
A. Mammen ◽  
V.K. Verma ◽  
C.V. Agarwal
2019 ◽  
Author(s):  
Wugen Huang ◽  
qingfei liu ◽  
Zhiwen Zhou ◽  
Yangsheng Li ◽  
Yong Wang ◽  
...  

Despite tremendous importance in catalysis, the design and improvement of the oxide- metal interface has been hampered by the limited understanding on the nature of interfacial sites, as well as the oxide-metal interaction (OMI). Through the construction of well-defined Cu<sub>2</sub>O-Pt, Cu<sub>2</sub>O-Ag, Cu<sub>2</sub>O-Au interfaces, we found that Cu<sub>2</sub>O Nanostructures (NSs) on Pt exhibit much lower thermal stability than on Ag and Au, although they show the same surface and edge structures, as identified by element-specific scanning tunneling microscopy (ES-STM) images. The activities of the Cu<sub>2</sub>O-Pt and Cu<sub>2</sub>O-Au interfaces for CO oxidation were further compared at the atomic scale and showed in general that the interface with Cu<sub>2</sub>O NSs could annihilate the CO-poisoning problem suffered by Pt group metals and enhance the interaction with O<sub>2</sub>, which is a limiting step for CO oxidation catalysis on group IB metals. While both interfaces could react with CO at room temperature, the OMI was found to determine the reactivity of supported Cu<sub>2</sub>O NSs by 1) tuning the activity of interfacial oxygen atoms and 2) stabilizing oxygen vacancies or vice versa, the dissociated oxygen atoms at the interface. Our study provides new insight for OMI and for the development of Cu-based catalysts for low temperature oxidation reactions.


2019 ◽  
Author(s):  
Wugen Huang ◽  
Yangsheng Li ◽  
Yong Wang ◽  
Yunchuan Tu ◽  
Dehui Deng ◽  
...  

Despite tremendous importance in catalysis, the design and improvement of the oxide- metal interface has been hampered by the limited understanding on the nature of interfacial sites, as well as the oxide-metal interaction (OMI). Through the construction of well-defined Cu<sub>2</sub>O-Pt, Cu<sub>2</sub>O-Ag, Cu<sub>2</sub>O-Au interfaces, we found that Cu<sub>2</sub>O Nanostructures (NSs) on Pt exhibit much lower thermal stability than on Ag and Au, although they show the same surface and edge structures, as identified by element-specific scanning tunneling microscopy (ES-STM) images. The activities of the Cu<sub>2</sub>O-Pt and Cu<sub>2</sub>O-Au interfaces for CO oxidation were further compared at the atomic scale and showed in general that the interface with Cu<sub>2</sub>O NSs could annihilate the CO-poisoning problem suffered by Pt group metals and enhance the interaction with O<sub>2</sub>, which is a limiting step for CO oxidation catalysis on group IB metals. While both interfaces could react with CO at room temperature, the OMI was found to determine the reactivity of supported Cu<sub>2</sub>O NSs by 1) tuning the activity of interfacial oxygen atoms and 2) stabilizing oxygen vacancies or vice versa, the dissociated oxygen atoms at the interface. Our study provides new insight for OMI and for the development of Cu-based catalysts for low temperature oxidation reactions.


2014 ◽  
Vol 13 (10) ◽  
pp. 2583-2592 ◽  
Author(s):  
Beenish Saba ◽  
Audil Rashid ◽  
Tariq Mahmood ◽  
Faisal Mehmood ◽  
Azeem Khalid ◽  
...  

1981 ◽  
Vol 48 (1) ◽  
pp. 30-34 ◽  
Author(s):  
G. R. Johnson

This paper demonstrates the capability to perform three-dimensional computations for explosive-metal interaction problems with complex sliding surfaces. An analysis is performed for an explosive device which accelerates a metal liner known as a self-forging fragment. Results are presented to show the effects of off-center detonation, asymmetric liner thickness, and asymmetric explosive density for an otherwise axisymmetric device. These three-dimensional conditions have little effect on the linear velocities, but they do introduce significant angular velocities to the self-forging fragment. Unlike projectile-target impact computations, which require only a single sliding surface between the projectile and the target, the explosive devices have multiple, intersecting, three-dimensional sliding surfaces between the expanding explosive gases and the various metal portions of the devices. Included are descriptions of the specialized “search routines” and the “double-pass” approach used for the explosive-metal interfaces.


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