Investigation of the reaction pathways in selective catalytic reduction of NO with NH{sub 3} over V{sub 2}O{sub 5} catalysts: Isotopic labeling studies using {sup 18}O{sub 2}, {sup 15}NH{sub 3}, {sup 15}NO, and {sup 15}N{sup 18}O{sup 1}

Journal Article · Sat Oct 01 00:00:00 EDT 1994 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1994.1306· OSTI ID:98932

Ozkan, U S; Cai, Y; Kumthekar, M W ^[1]

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1. Ohio State Univ., Columbus, OH (United States)

Isotopic tracer studies were performed to investigate the reaction network of selective catalytic reduction of nitric oxide over vanadia catalysts having preferential exposure of different crystal planes. The catalysts were characterized using BET surface area analysis, X-ray diffraction, laser Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, 3-D imaging, and thermal analysis techniques. The product analysis was carried out by a combination of chemiluminescence NO{sub x} analysis, gas chromatography-mass spectrometry, and chemical titration methods. The isotropic labeling experiments were performed under steady state reaction conditions by using NH{sub 3} + NO + {sup 16}O{sub 2} {r_arrow} NH{sub 3} + NO + {sup 18}O{sub 2}, {sup 14}NH{sub 3} + NO + O{sub 2} {r_arrow} {sup 15}NH{sub 3} + NO + O{sub 2}, NH{sub 3} + {sup 14}NO + O{sub 2} {r_arrow} NH{sub 3} + {sup 15}NO + O{sub 2}, and NH{sub 3} + {sup 14}N{sup 16}O + {sup 16}O{sub 2} {r_arrow} NH{sub 3} + {sup 15}N{sub 18}O + {sup 18}O{sub 2} switches. Interaction of NO with the vanadia surface was also studied using a {sup 14}N{sup 16}O {r_arrow} {sup 15}N{sup 18}O switch. The results obtained in these experiments were combined with the tracer studies performed in ammonia oxidation reactions over the same catalysts to elucidate the reaction pathways involved in SCR reactions, to compare the surface residence times of nitrogen containing species, as well as to quantify the role of ammonia oxidation in SCR reactions. 35 refs., 14 figs., 3 tabs.

• OSTI ID: 98932
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 149; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
33 ADVANCED PROPULSION SYSTEMS
40 CHEMISTRY
CATALYTIC EFFECTS
CHEMILUMINESCENCE
GAS CHROMATOGRAPHY
LABELLING
MASS SPECTROSCOPY
NITRIC OXIDE
NITROGEN 15
OXYGEN 18
PHOTOELECTRON SPECTROSCOPY
RAMAN EFFECT
SCANNING ELECTRON MICROSCOPY
SELECTIVE CATALYTIC REDUCTION
SURFACE AREA
THERMAL ANALYSIS
TITRATION
VANADIUM OXIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY