NO oxidation activity of Ag-doped perovskite catalysts

Display Omitted * NO oxidation activity of LaMnO3 is enhanced by the partial substitution of Ag+ for La3+ . * La1-xAg x MnO3 reveals the maximum NO oxidation rate based on the surface area at x =0.2. * Oxygen vacancies interacted with Ag+ are the active reaction sites on La1-xAg x MnO3. * Key reacti...

Full description

Saved in:
Bibliographic Details
Published inJournal of catalysis Vol. 319; pp. 182 - 193
Main Authors DAL YOUNG YOON, EUNHO LIM, YOUNG JIN KIM, JI HO KIM, TAEKYUNG RYU, SUMIN LEE, CHO, Byong K, NAM, In-Sik, JIN WOO CHOUNG, SEUNGBEOM YOO
Format Journal Article
LanguageEnglish
Published Amsterdam Elsevier 01.11.2014
Elsevier BV
Subjects
Catalysis
Catalysts
Chemistry
Exact sciences and technology
General and physical chemistry
Nitric oxide
Oxidation
Perovskite
Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
Oxygen
Perovskite type compound
Vacancy
Ag
NO oxidation
Nitrates
MnO
Heterogeneous catalysis
Perovskite
Nitrate
La
Oxidation
Catalyst
Oxygen vacancy
Online AccessGet full text

Cover

More Information
Summary:Display Omitted * NO oxidation activity of LaMnO3 is enhanced by the partial substitution of Ag+ for La3+ . * La1-xAg x MnO3 reveals the maximum NO oxidation rate based on the surface area at x =0.2. * Oxygen vacancies interacted with Ag+ are the active reaction sites on La1-xAg x MnO3. * Key reaction intermediates are mono- and bi-dentate nitrates on oxygen vacancies. Ag-doped perovskite catalysts (La1- x Ag x MnO3) prepared by the citric acid method were investigated for the catalytic oxidation of NO. Compared to LaMnO3, La1- x Ag x MnO3 revealed a superior NO oxidation activity with its maximum activity at x =0.2, confirming the potential of La0.8Ag0.2MnO3 as one of the most promising NO oxidation catalysts. The high reactivity of La0.8Ag0.2MnO3 is mainly due to the high oxygen vacancy concentration on its surface produced by the partial substitution of La3+ with Ag+ in LaMnO3, as determined by the XRD, SEM, XPS, O2-TPD, H2-TPR, (NO+O2)-TPRD and DRIFT studies. The mono- and bi-dentate nitrates formed on the oxygen vacancies of perovskite appear to be the primary reaction intermediates for the NO oxidation reaction over the Ag-doped perovskite catalyst. A plausible reaction pathway of the NO oxidation over La1- x Ag x MnO3 has been postulated on the basis of the redox process involving the oxygen vacancy, oxygen, NO, NO2 and NO3.
ISSN:0021-9517
1090-2694
DOI:10.1016/j.jcat.2014.09.007