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]

---

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, Vol. 149, Issue 2; Other Information: PBD: Oct 1994
• Country of Publication: United States
• Language: English

Related Subjects

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