Post-Hartree-Fock (MP2 and MP4) study on decomposition of nitrous oxide on the nonframework AlO(+) site in ZSM-5 zeoliteстатья
Информация о цитировании статьи получена из
Web of Science ,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Авторы:
Solkan V.N. ,
Zhidomirov G.M.
Журнал:
International Journal of Quantum Chemistry
Том:
111
Номер:
11
Год издания:
2011
Издательство:
John Wiley & Sons Inc.
Местоположение издательства:
United States
Первая страница:
2639
Последняя страница:
2648
DOI:
10.1002/qua.22819
Аннотация:
The reaction mechanism for nitrous oxide (N 2O) decomposition has been studied on AlO(+) site in AlO-ZSM-5 zeolite using the MP2/6-31+G(d) method. The active centers were taken to be mononuclear [AlO] + and [AlO 2] +, and the surrounding portion of the zeolite was represented by a 3T cluster, namely [AlSi 2O 4H 8] -. The first elementary step of N 2O decomposition involves the formation of [AlO 2] + and the release of N 2. The metal-peroxo species produced in this step then reacts with N 2O again, to release N 2 and form [AlO 3] +. The calculated activation energies at MP2 level for N 2O dissociation on AlO-ZSM-5 and AlO 2-ZSM-5 are 26.9 and 38.2 kcal/mol at 298 K, respectively. The calculated reaction enthalpies at MP2 level for N 2O dissociation on AlO-ZSM-5 and AlO 2-ZSM-5 are -25.1 and -21.3 kcal/mol at 298 K, respectively. Four-order perturbation theory (MP4//MP2) predicts that the activation barriers for N 2O dissociation at 298 K on AlO-ZSM-5 and AlO 2-ZSM-5 are 12.9 and 29.5 kcal/mol, respectively. The calculated energy for desorption of singlet O 2 from the 3T -[Al(O) 3] + cluster at MP2 level is 46.4 kcal/mol. When one takes into account the entropy gained on desorption of singlet O 2, the contribution of entropy to the free energy of desorption is TΔS = 11.1 kcal/mol at 298 K. Copyright © 2010 Wiley Periodicals, Inc.
Добавил в систему:
Жидомиров Георгий Михайлович