Effect of CeO2 for a high-efficiency CeO2/WO3–TiO2 catalyst on N2O formation in NH3-SCR: a kinetic study

2016 ◽  
Vol 6 (9) ◽  
pp. 3149-3155 ◽  
Author(s):  
Yang Geng ◽  
Wenpo Shan ◽  
Shangchao Xiong ◽  
Yong Liao ◽  
Shijian Yang ◽  
...  

The effect of CeO2 for a high-efficiency CeO2/WO3–TiO2 catalyst on N2O formation in NH3-SCR reaction was investigated using a kinetic method.

2015 ◽  
Vol 179 ◽  
pp. 185-195 ◽  
Author(s):  
Nicola Usberti ◽  
Magdalena Jablonska ◽  
Miriam Di Blasi ◽  
Pio Forzatti ◽  
Luca Lietti ◽  
...  

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 618
Author(s):  
Huan Du ◽  
Zhitao Han ◽  
Xitian Wu ◽  
Chenglong Li ◽  
Yu Gao ◽  
...  

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.


Vacuum ◽  
2021 ◽  
pp. 110384
Author(s):  
Junqiang Xu ◽  
Xianlin Zou ◽  
Guorong Chen ◽  
Yanrong Zhang ◽  
Qiang Zhang ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11226-11232 ◽  
Author(s):  
Ning-zhi Yang ◽  
Rui-tang Guo ◽  
Qing-shan Wang ◽  
Wei-guo Pan ◽  
Qi-lin Chen ◽  
...  

The deactivation mechanism of phosphorous on a Mn/TiO2 catalyst for selective catalytic reduction of NO with NH3 was investigated in this study.


2017 ◽  
Vol 60 (9-11) ◽  
pp. 755-762 ◽  
Author(s):  
Young Eun Jeong ◽  
Pullur Anil Kumar ◽  
Danh Thi Huong ◽  
Heon Phil Ha ◽  
Kwan-Young Lee
Keyword(s):  

2017 ◽  
Vol 7 (20) ◽  
pp. 4669-4679 ◽  
Author(s):  
Zhouyang Liu ◽  
Vishnu Sriram ◽  
Can Li ◽  
Joo-Youp Lee

A mechanistic study using in situ DRIFTS and a kinetic study were conducted on a ruthenium oxide based mercury oxidation catalyst.


Author(s):  
Jie Yang ◽  
Shan Ren ◽  
Mingming Wang ◽  
Zhicaho Chen ◽  
Lin Chen ◽  
...  

Ce–Ti catalysts were considered as promising replacement for V–Ti based catalysts for selective catalytic reduction (SCR) of nitrogen oxides (NO and NO2) with NH3. In this work, CeO2/TiO2 catalyst was...


Author(s):  
Robert B. Jordan

A kinetic study generally proceeds after the reactants, products and stoichiometry of the reaction have been satisfactorily characterized. The more one knows about the chemistry of the reaction, the better the conclusions that one can draw from a kinetic study. The discussion here describes techniques often used in inorganic studies, emphasizes their time range and general area of applicability and gives some examples of their use. Further details can be found in other sources. Any experimental kinetic method must somehow monitor change of concentration with time. Many studies are done under pseudo-first-order conditions, and then one must monitor the deficient reactant or product(s) because the other species undergo small changes in concentration. The kinetic method(s) of choice often will be dictated by the time scale of the reaction. The detection method(s) will be determined by the spectroscopic properties of the species to be monitored. The efficient use of materials can be a significant factor in the choice of method because a kinetic study generally involves a number of runs at different concentrations and temperatures, and conservation of difficult to prepare or expensive reagents may be a critical factor. The detection method should be as species specific as possible, and ideally one would like to measure both reactant disappearance and product formation. The method must not be subject to interference from other reactants and should be applicable under a wide range of concentration conditions so that the rate law can be fully explored. Often there is a practical trade-off between specificity, sensitivity and reaction time. For example, NMR is quite specific but rather slow and has relatively low sensitivity, unless the system allows time for signal accumulation. Spectrophotometry in the UV and visible range often has good sensitivity and speed, but the specificity may be poor because absorbance bands are broad and intermediates may have chromophoric properties similar to those of the reactant and/or product. Vibrational Spectrophotometry can be better if the IR bands are sharp, as in the case of metal carbonyls, but the solvent must be chosen to provide an appropriate spectral window.


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