The catalytic oxidation removal of low-concentration HCHO at high space velocity by partially crystallized mesoporous MnO x

2017 ◽  
Vol 320 ◽  
pp. 667-676 ◽  
Author(s):  
Min Wang ◽  
Lingxia Zhang ◽  
Weimin Huang ◽  
Tongping Xiu ◽  
Chenggang Zhuang ◽  
...  
2011 ◽  
Vol 383-390 ◽  
pp. 3092-3098 ◽  
Author(s):  
Kai Li ◽  
Xiao Long Tang ◽  
Hong Hong Yi ◽  
Ping Ning ◽  
Zhi Qing Ye ◽  
...  

Mn-Ni-Ox catalyst was prepared by the co-precipitation method. The most active catalysts were obtained with a molar Ni/ (Mn+Ni) ratio of 0.1. The results showed that over this catalyst, NO oxidation conversion reached 59% at 125°C and 50% at 150°C with a high space velocity of 35000h-1. Their surface properties were evaluated by means of scanning electron microscopy (SEM). The process of non-thermal plasma-assisted catalytic oxidation of NO under low-temperature was studied. And the NO conversion could reach 80% with the non-thermal plasma-assisting at 150°C when the input voltage was 30V. The increasing activities at low temperature(50~175°C)were more apparently higher than high temperature by plasma. And the low-temperature catalytic activity of the catalyst was increased with the increase of the input voltage.


Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 592 ◽  
Author(s):  
Wenpo Shan ◽  
Yang Geng ◽  
Yan Zhang ◽  
Zhihua Lian ◽  
Hong He

In this study, CeZr0.5TiaOx (with a = 0, 1, 2, 5, 10) catalysts were prepared by a stepwise precipitation approach for the selective catalytic reduction of NOx with NH3. When Ti was added, all of the Ce-Zr-Ti oxide catalysts showed much better catalytic performances than the CeZr0.5Ox. Particularly, the CeZr0.5Ti2Ox catalyst showed excellent activity for broad temperature range under high space velocity condition. Through the control of pH value and precipitation time during preparation, the function of the CeZr0.5Ti2Ox catalyst could be controlled and the structure with highly dispersed CeO2 (with redox functions) on the surface of ZrO2-TiO2 (with acidic functions) could be obtained. Characterizations revealed that the superior catalytic performance of the catalyst is associated with its outstanding redox properties and adsorption/activation functions for the reactants.


1986 ◽  
Vol 109 ◽  
pp. 247-251
Author(s):  
A. R. Upgren

The present astrometric program of the Van Vleck Observatory began in 1967. Since then it has emphasized parallaxes and proper motions of stars of the lower main sequence which are not identified on the basis of proper motion and are therefore not biased towards high space velocity. Later an analysis was made from parallax and proper motion data from 70 stars in the spectral range dK3-M2 (Upgren 1973) which found the average external mean error in parallax to be 8.0 ± 1.7 mas (milliarcseconds). This external error was found to vary little from one parallax to another and to have no correlation with the formal internal errors for the individual parallax determinations. Hanson and Lutz (1983) confirm this result using the parallaxes of 14 members of the Hyades cluster also determined at Van Vleck. They find a mean external parallax error of 9.4 ± 1.8 mas and suggest that the proximity of the two determinations may be evidence that Van Vleck parallaxes may be characterized by a single external error. Their slightly larger figure may or may not reflect the relatively fewer plates and epochs of observation from which the Hyades parallaxes were determined.


1952 ◽  
Vol 44 (8) ◽  
pp. 1811-1817 ◽  
Author(s):  
R. C. Archibald ◽  
N C. May ◽  
B. S. Greensfelder

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