Isotopic labeling studies of the effects of temperature, water, and vanadia loading on the selective catalytic reduction of NO with NH[sub 3] over vanadia-titania catalysts

Journal Article · Thu Jul 21 00:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100080a010· OSTI ID:6960111

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

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

Isotopic labeling studies of the reaction between [sup 15]NO and [sup 14]NH[sub 3] have been performed over a range of vanadia-titania-based SCR catalysts (pure V[sub 2]O[sub 5] and catalysts containing 1.4-23.2 wt% V[sub 2]O[sub 5]) for the extended temperature range of 200-500[degree]C. For temperatures less than 350[degree]C, [sup 14]N[sup 15]N is always the major product. At higher temperatures, however, product distributions are very sensitive to vanadia content; ammonia oxidation to [sup 14]NO is particularly dominant for pure V[sub 2]O[sub 5] and, at 500[degree]C, accounts for more than 70% of the nitrogen-containing products. Pure V[sub 2]O[sub 5] also produces significantly more [sup 14]N[sup 15]NO, and at much lower temperatures, than that observed for a 1.4 wt % V[sub 2]O[sub 5]/TiO[sub 2] catalyst. On the basis of these results it is clear that ammonia oxidation to [sup 14]NO is the major reason for the observed decrease in the NO conversion over vanadia-based catalysts at temperatures greater than 400[degree]C. Ammonia oxidation to nitrogen and nitrous oxide is less significant; [sup 14]N[sub 2]O and [sup 14]N[sub 2] each comprise less than 10% of the total products for both the pure and supported vanadia catalysts. 36 refs., 6 figs., 3 tabs.

• OSTI ID: 6960111
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 98:29; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMMONIA
OXIDATION
NITRIC OXIDE
REDUCTION
CATALYSTS
COMPILED DATA
FLUE GAS
FOSSIL-FUEL POWER PLANTS
LABELLED COMPOUNDS
NITROGEN 14
NITROGEN 15
NITROUS OXIDE
TITANIUM OXIDES
VANADIUM OXIDES
WATER
X-RAY DIFFRACTION
CHALCOGENIDES
CHEMICAL REACTIONS
COHERENT SCATTERING
DATA
DIFFRACTION
GASEOUS WASTES
HYDRIDES
HYDROGEN COMPOUNDS
INFORMATION
ISOTOPES
LIGHT NUCLEI
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN ISOTOPES
NITROGEN OXIDES
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OXIDES
OXYGEN COMPOUNDS
POWER PLANTS
SCATTERING
STABLE ISOTOPES
THERMAL POWER PLANTS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
VANADIUM COMPOUNDS
WASTES
200202* - Fossil-Fueled Power Plants- Waste Management- Noxious Gas & Particulate Emissions
400201 - Chemical & Physicochemical Properties