Evaluation of energy distribution on a heterogeneous surface from heat of adsorption and its application to the ammonia/Na-Y zeolite system

1985 ◽  
Vol 263 (10) ◽  
pp. 838-841 ◽  
Author(s):  
K. Tsutsumi ◽  
Y. Mitani ◽  
H. Takahashi
2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kim Choon Ng ◽  
Muhammad Burhan ◽  
Muhammad Wakil Shahzad ◽  
Azahar Bin Ismail

Author(s):  
Tamotsu Ohno

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.


Author(s):  
Clifford S. Rainey

The spatial distribution of V and Ni deposited within fluidized catalytic cracking (FCC) catalyst is studied because these metals contribute to catalyst deactivation. Y zeolite in FCC microspheres are high SiO2 aluminosilicates with molecular-sized channels that contain a mixture of lanthanoids. They must withstand high regeneration temperatures and retain acid sites needed for cracking of hydrocarbons, a process essential for efficient gasoline production. Zeolite in combination with V to form vanadates, or less diffusion in the channels due to coke formation, may deactivate catalyst. Other factors such as metal "skins", microsphere sintering, and attrition may also be involved. SEM of FCC fracture surfaces, AEM of Y zeolite, and electron microscopy of this work are developed to better understand and minimize catalyst deactivation.


2008 ◽  
Vol 42 (2) ◽  
pp. 125-128
Author(s):  
J. F. Al-Sharab ◽  
J. E. Wittig ◽  
G. Bertero ◽  
T. Yamashita ◽  
J. Bentley ◽  
...  

1979 ◽  
Vol 40 (C7) ◽  
pp. C7-385-C7-386
Author(s):  
S. Bourquard ◽  
J. M. Mayor ◽  
P. Kocian

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