Isotopic evidence for direct conversion of NO to NH[sub 3] in the absence of O[sub 2] over V[sub 2]O[sub 5]/TiO[sub 2] and [alpha]-Cr[sub 2]O[sub 3] selective catalytic reduction catalysts

Journal Article · Thu Mar 04 04:00:00 EST 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100111a002· OSTI ID:6051944

Duffy, B L; Curry-Hyde, H E ^[1]; Cant, N W ^[2]; Nelson, P F ^[3]

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1. Univ. of New South Wales, Kensington (Australia)
2. Macquarie Univ., North Ryde (Australia)
3. CSIRO Division of Coal and Energy Technology, North Ryde (Australia)

The products of the reaction between [sup 15]NO and [sup 14]NH[sub 3] over V[sub 2]O[sub 5]/TiO[sub 2]and [alpha]-Cr[sub 2]O[sub 3] catalysts in the absence of oxygen have been determined by mass spectrometry and Fourier transform infrared spectroscopy. With both catalysts [sup 14]N[sup 15]N comprises approximately two-thirds of the nitrogen-containing products. Very surprisingly, [sup 15]NH[sub 3] makes up about one-half the remainder. This has significant implications for the likely mechanism of the SCR reaction in the absence of oxygen. Formation of [sup 15]NH[sub 3] by direct exchange of both hydrogen and oxygen between [sup 14]NH[sub 3] and [sup 15]NO molecules can be ruled out since no [sup 14]NO is produced. It seems that [sup 15]NO is broken down to separate [sup 15]N and oxygen species on reduced sites and that [sup 15]NH[sub 3] can then be made by reaction of the [sup 15]N species with water. It is possible that the nitrogen-containing species is an NH group. With V[sub 2]O[sub 5]/TiO[sub 2] the only remaining product is [sup 14]N[sup 15]NO. However, this is largely replaced by doubly labeled products, [sup 14]N[sub 2], [sup 15]N[sub 2], and [sup 15]N[sub 2]O, when using [alpha]-Cr[sub 2]O[sub 3]. 22 refs., 1 fig., 2 tabs.

• OSTI ID: 6051944
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 97:9; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

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