Formation of Ammonia during the NO-H-2 Reaction over Pt/ZrO2

T. Nanba; Frederic Meunier; Christopher Hardacre; J.P. Breen; Robbie Burch; S. Masukawa; J. Uchisawa; A. Obuchi

doi:10.1021/jp8060812

Formation of Ammonia during the NO-H-2 Reaction over Pt/ZrO2

T. Nanba, Frederic Meunier, Christopher Hardacre, J.P. Breen, Robbie Burch, S. Masukawa, J. Uchisawa, A. Obuchi

School of Chemistry and Chemical Engineering

Research output: Contribution to journal › Article › peer-review

15 Citations (Scopus)

Abstract

The mechanism for the formation of NH3 during the NO-H-2 reaction over Pt/ZrO2 was studied. Steady-state isotopic transient kinetic analysis was carried out with isotopic switching from (NO)-N-15-D-2 to (NO)-N-14-D-2, and the results revealed that formation of N-2 and N2O was associated with linearly adsorbed NO on the Pt surface, whereas ammonia formation was associated with NDx species adsorbed on ZrO2. The adsorbed NHx species were not observed on the surface of ZrO2 during NH3 adsorption. From transient kinetic experiments, the formation rates of NHx species and of gaseous NH3 agreed with each other, suggesting that the NHx species on ZrO2 was an ammonia intermediate. The NDx species did not react with D-2 directly, but H-D exchange occurred easily. The addition of H2O to the NO-H-2 feed gas enhanced the formation of NH3. In situ diffuse reflectance spectra and transient kinetic analysis revealed that H2O enhanced the conversion of NHx species to NH3.

Original language	English
Pages (from-to)	18157-18163
Number of pages	7
Journal	Journal of Physical Chemistry C
Volume	112
Issue number	46
DOIs	https://doi.org/10.1021/jp8060812
Publication status	Published - 20 Nov 2008

ASJC Scopus subject areas

Physical and Theoretical Chemistry
General Energy
Electronic, Optical and Magnetic Materials
Surfaces, Coatings and Films

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title = "Formation of Ammonia during the NO-H-2 Reaction over Pt/ZrO2",

abstract = "The mechanism for the formation of NH3 during the NO-H-2 reaction over Pt/ZrO2 was studied. Steady-state isotopic transient kinetic analysis was carried out with isotopic switching from (NO)-N-15-D-2 to (NO)-N-14-D-2, and the results revealed that formation of N-2 and N2O was associated with linearly adsorbed NO on the Pt surface, whereas ammonia formation was associated with NDx species adsorbed on ZrO2. The adsorbed NHx species were not observed on the surface of ZrO2 during NH3 adsorption. From transient kinetic experiments, the formation rates of NHx species and of gaseous NH3 agreed with each other, suggesting that the NHx species on ZrO2 was an ammonia intermediate. The NDx species did not react with D-2 directly, but H-D exchange occurred easily. The addition of H2O to the NO-H-2 feed gas enhanced the formation of NH3. In situ diffuse reflectance spectra and transient kinetic analysis revealed that H2O enhanced the conversion of NHx species to NH3.",

author = "T. Nanba and Frederic Meunier and Christopher Hardacre and J.P. Breen and Robbie Burch and S. Masukawa and J. Uchisawa and A. Obuchi",

year = "2008",

month = nov,

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doi = "10.1021/jp8060812",

language = "English",

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pages = "18157--18163",

journal = "Journal of Physical Chemistry C",

issn = "1932-7447",

publisher = "American Chemical Society",

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TY - JOUR

T1 - Formation of Ammonia during the NO-H-2 Reaction over Pt/ZrO2

AU - Nanba, T.

AU - Meunier, Frederic

AU - Hardacre, Christopher

AU - Breen, J.P.

AU - Burch, Robbie

AU - Masukawa, S.

AU - Uchisawa, J.

AU - Obuchi, A.

PY - 2008/11/20

Y1 - 2008/11/20

N2 - The mechanism for the formation of NH3 during the NO-H-2 reaction over Pt/ZrO2 was studied. Steady-state isotopic transient kinetic analysis was carried out with isotopic switching from (NO)-N-15-D-2 to (NO)-N-14-D-2, and the results revealed that formation of N-2 and N2O was associated with linearly adsorbed NO on the Pt surface, whereas ammonia formation was associated with NDx species adsorbed on ZrO2. The adsorbed NHx species were not observed on the surface of ZrO2 during NH3 adsorption. From transient kinetic experiments, the formation rates of NHx species and of gaseous NH3 agreed with each other, suggesting that the NHx species on ZrO2 was an ammonia intermediate. The NDx species did not react with D-2 directly, but H-D exchange occurred easily. The addition of H2O to the NO-H-2 feed gas enhanced the formation of NH3. In situ diffuse reflectance spectra and transient kinetic analysis revealed that H2O enhanced the conversion of NHx species to NH3.

AB - The mechanism for the formation of NH3 during the NO-H-2 reaction over Pt/ZrO2 was studied. Steady-state isotopic transient kinetic analysis was carried out with isotopic switching from (NO)-N-15-D-2 to (NO)-N-14-D-2, and the results revealed that formation of N-2 and N2O was associated with linearly adsorbed NO on the Pt surface, whereas ammonia formation was associated with NDx species adsorbed on ZrO2. The adsorbed NHx species were not observed on the surface of ZrO2 during NH3 adsorption. From transient kinetic experiments, the formation rates of NHx species and of gaseous NH3 agreed with each other, suggesting that the NHx species on ZrO2 was an ammonia intermediate. The NDx species did not react with D-2 directly, but H-D exchange occurred easily. The addition of H2O to the NO-H-2 feed gas enhanced the formation of NH3. In situ diffuse reflectance spectra and transient kinetic analysis revealed that H2O enhanced the conversion of NHx species to NH3.

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U2 - 10.1021/jp8060812

DO - 10.1021/jp8060812

M3 - Article

SN - 1932-7447

VL - 112

SP - 18157

EP - 18163

JO - Journal of Physical Chemistry C

JF - Journal of Physical Chemistry C

IS - 46

ER -

Formation of Ammonia during the NO-H-2 Reaction over Pt/ZrO2

Abstract

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