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Indexed by:Journal Papers

Date of Publication:2015-06-16

Journal:SEPARATION AND PURIFICATION TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:147

Page Number:24-31

ISSN No.:1383-5866

Key Words:NH3 oxidation; Ce0.4Zr0.6O2 catalyst; Al modified; Oxygen species; Oxygen vacancy

Abstract:A novel Al doped Ce0.4Zr0.6O2 catalyst prepared by surfactant-templated method was tested for NH3 selective oxidation, and it was found that the addition of an appropriate amount of Al to Ce0.4Zr0.6O2 catalysts improved the NH3 oxidation activity. Strikingly, the NH3 conversion obtained on 3% Al-Ce0.4Zr0.6O2 catalyst was, on average, 12.7% higher than that of undoped Ce0.4Zr0.6O2 catalyst. The XRD and H-2-TPR results showed that the inclusion of Al components resulted in the formation of smaller sized CeO2 (4.4-5.8 nm), and improved the oxygen mobility and reducibility. The normalized BET and NH3-TPD analysis also confirmed that the adsorption centers for NH3 in Al-Ce0.4Zr0.6O2 catalysts was increased with the Al addition. More importantly, the oxygen vacancies, of which the amount was increased by modification of Al, were considered as the essential oxygen adsorption and activation sites. Consequently, more active oxygen species (O- and O2-) were formed, which facilitated the NH3 oxidation reaction. (C) 2015 Elsevier B.V. All rights reserved.