Quantum chemistry study on the oxidation of NO catalyzed by ZSM5 supported Mn/Co–Al/Ce

2017 ◽  
Vol 16 (05) ◽  
pp. 1750044 ◽  
Author(s):  
Zhengcheng Wen ◽  
Mengmeng Du ◽  
Yuan Li ◽  
Zhihua Wang ◽  
Jiangrong Xu ◽  
...  

The detailed mechanism of NO oxidation catalyzed by ZSM5 supported Mn/Co–Al/Ce is investigated and revealed by Quantum Chemistry Calculation. A three-step catalytic mechanism for NO oxidation is proposed and studied. Theoretical results show that, the activate energies of reactions catalyzed by ZSM-5 supported Mn/Co (71.1[Formula: see text]kJ/mol/80.6[Formula: see text]kJ/mol) are much lower than that obtained from the direct NO oxidation. This indicates that the ZSM-5 supported Mn/Co has an obvious catalytic effect. When the active center Si is replaced by Al and Ce, the activation energies are further decreased to about 40[Formula: see text]kJ/mol. This indicates that the doping of Al and Ce can obviously improve the catalytic effect. The theoretical study illustrates that the catalysts for NO oxidation not only relate to the supported transition metal such as Co and Mn, but also highly relate to the activity centers such as Al and Ce.

2013 ◽  
Vol 787 ◽  
pp. 301-305
Author(s):  
Yun Bo He ◽  
Wei Wang ◽  
Shi Xiong Wang ◽  
Xiang Jun Yang ◽  
Hong Guo

The thermal decomposition of organic peroxides are widely used as coagulant for organic compounds, however, its thermal hazardous characteristics have already caused serious accidents in chemical industries, which limited its application in much more strict conditions. Organic peroxides of C18H10O11 and C18H18O7 are two new candidates fitted for industrial explosive. However, as we best known there is little reports available on the geometry structure in the past decades. In this work, by means of quantum chemistry calculation, the relation of safety with molecular structure of C18H10O11 and C18H18O7 are discussed. The molecules with more activity O and the activity part more dispersedly exhibit higher stable, and the configuration has good safety. All the energy of molecule b is higher than that of molecule a. The stability of different configurations are 6a>7a>8a>9a>5a>1a>4a>3a=2a and 1b>7b>5b>6b>4b>2b>3b>8b, respectively, suggesting the structures of 6a,3a,2a,1b,8b exhibit high safety.


2003 ◽  
Vol 119 (1) ◽  
pp. 325-337 ◽  
Author(s):  
L. F. Errea ◽  
A. Macı́as ◽  
L. Méndez ◽  
B. Pons ◽  
A. Riera

1999 ◽  
Vol 64 (10) ◽  
pp. 1673-1695 ◽  
Author(s):  
Jiří Šibor ◽  
Dalimil Žůrek ◽  
Radek Marek ◽  
Michal Kutý ◽  
Otakar Humpa ◽  
...  

Synthesis of 2-(3-acylselenoureido)benzonitriles and 2-(3-acylselenoureido)thiophene- 3-carbonitriles 5a-5f by addition of 2-aminonitriles 4a-4c to benzoyl- or 2,2-dimethyl- propanoylisoselenocyanate and their cycloaddition reactions are described. Structures of compounds 5a-5f were supported by CIMS, FTIR, 1H, 13C, 77Se and 15N NMR spectra. The parameters of 15N and 77Se nuclei were obtained from inverse 1H-X 2D HMBC and GSQMBC correlation experiments at natural abundance. Structure of compound 5b was confirmed by X-ray analysis. The geometry of 5b was optimized by ab initio RHF/DZVP quantum chemistry calculation. A very good correlation between the calculation and experimental data was found. The geometry of 5e was optimized by ab initio DFT/VWN/DZVP quantum chemistry calculation. It was found that title compounds 5a-5f do not undergo isomerization to acylisoselenoureas, in contrast to analogous ester derivatives. Fused 6-imino-6H-1,3- selenazinium salts (chlorides 6a-6f, hydrogensulfates 7a-7f and tetrafluoroborates 8a-8f) were prepared by an acid cyclization of 5a-5f. It was found that neutralization of 6a-6f, 7a-7f and 8a-8f led to their retrocyclization to 5a-5f. Selenoureas 5a-5f with equimolar amounts of methanolic potassium hydroxide afforded potassium salts 9a-9f. Only the salts 9b, 9c, 9e and 9f of the thiophene series were isolated. Their heating in methanol solution led to deacylation of isoselenoureas 10b and 10c. The in situ prepared compounds 9a and 9d cyclized and deacylated to 4-aminoquinazoline-2-selenole 11a under the same conditions. The compounds 5a-5f and 10a-10c cyclized to fused 4-aminopyrimidine-2-selenols 11a, 11b and 4-aminopyrimidine-2-selenone 12c by boiling in methanolic potassium hydroxide solution.


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