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Title: Kinetics, kinetic deuterium isotope effects, and mechanism of nitrous oxide reaction with hydrogen on supported precious-metal catalysts

Abstract

The kinetics and kinetic deuterium isotope effects have been precisely measured for the reaction of nitrous oxide with hydrogen on Ru/Al/sub 2/O/sub 3/, Rh/Al/sub 2/O/sub 3/, Ir/Al/sub 2/O/sub 3/, and Pt/Al/sub 2/O/sub 3/ catalysts. The reaction apparently proceeds through the two following elementary steps: N/sub 2/O + M ..-->.. N/sub 2/ + M=O (reaction 1) and M=O + H/sub 2/ ..-->.. M + H/sub 2/O (reaction 2). In reaction 1, an N/sub 2/O molecule attacks the vacant metal site on the surface (M) to form an N/sub 2/ molecule and an adsorbed oxygen atom (M=O). In reaction 2, the reaction of the surface oxygen atom with an H/sub 2/ molecule takes place to form an H/sub 2/O molecule and the vacant metal site. The activation energy for reaction 1 increases in the order Ru/Al/sub 2/O/sub 3/ < Rh/Al/sub 2/O/sub 3/ < Ir/Al/sub 2/O/sub 3/ < Pt/Al/sub 2/O/sub 3/, whereas for reaction 2 the activation energy decreases in the order Ru/Al/sub 2/O/sub 3/ > Rh/Al/sub 2/O/sub 3/ > Ir/Al/sub 2/O/sub 3/. The preexponential factors of the rate constant for both reactions 1 and 2 do not vary significantly from one catalyst to another, although the value for reaction 1 is aboutmore » 10/sup 4/ times smaller than that for reaction 2. The experimental results have been satisfactorily explained with the transition-state theory coupled with the above-mentioned reaction mechanism.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Nagoya Univ., Japan
OSTI Identifier:
6071830
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem.; (United States)
Additional Journal Information:
Journal Volume: 85:21
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ALUMINIUM OXIDES; CATALYTIC EFFECTS; DEUTERIUM; ISOTOPE EFFECTS; HYDROGEN; CHEMICAL REACTION KINETICS; IRIDIUM; NITROUS OXIDE; PLATINUM; RHODIUM; RUTHENIUM; CATALYST SUPPORTS; COMPARATIVE EVALUATIONS; EXPERIMENTAL DATA; ALUMINIUM COMPOUNDS; CHALCOGENIDES; DATA; ELEMENTS; HYDROGEN ISOTOPES; INFORMATION; ISOTOPES; KINETICS; LIGHT NUCLEI; METALS; NITROGEN COMPOUNDS; NITROGEN OXIDES; NONMETALS; NUCLEI; NUMERICAL DATA; ODD-ODD NUCLEI; OXIDES; OXYGEN COMPOUNDS; PLATINUM METALS; REACTION KINETICS; REFRACTORY METALS; STABLE ISOTOPES; TRANSITION ELEMENTS; 400202* - Isotope Effects, Isotope Exchange, & Isotope Separation

Citation Formats

Mlyamoto, A, Baba, S, Mori, M, and Murakami, Y. Kinetics, kinetic deuterium isotope effects, and mechanism of nitrous oxide reaction with hydrogen on supported precious-metal catalysts. United States: N. p., 1981. Web. doi:10.1021/j150621a022.
Mlyamoto, A, Baba, S, Mori, M, & Murakami, Y. Kinetics, kinetic deuterium isotope effects, and mechanism of nitrous oxide reaction with hydrogen on supported precious-metal catalysts. United States. https://doi.org/10.1021/j150621a022
Mlyamoto, A, Baba, S, Mori, M, and Murakami, Y. Thu . "Kinetics, kinetic deuterium isotope effects, and mechanism of nitrous oxide reaction with hydrogen on supported precious-metal catalysts". United States. https://doi.org/10.1021/j150621a022.
@article{osti_6071830,
title = {Kinetics, kinetic deuterium isotope effects, and mechanism of nitrous oxide reaction with hydrogen on supported precious-metal catalysts},
author = {Mlyamoto, A and Baba, S and Mori, M and Murakami, Y},
abstractNote = {The kinetics and kinetic deuterium isotope effects have been precisely measured for the reaction of nitrous oxide with hydrogen on Ru/Al/sub 2/O/sub 3/, Rh/Al/sub 2/O/sub 3/, Ir/Al/sub 2/O/sub 3/, and Pt/Al/sub 2/O/sub 3/ catalysts. The reaction apparently proceeds through the two following elementary steps: N/sub 2/O + M ..-->.. N/sub 2/ + M=O (reaction 1) and M=O + H/sub 2/ ..-->.. M + H/sub 2/O (reaction 2). In reaction 1, an N/sub 2/O molecule attacks the vacant metal site on the surface (M) to form an N/sub 2/ molecule and an adsorbed oxygen atom (M=O). In reaction 2, the reaction of the surface oxygen atom with an H/sub 2/ molecule takes place to form an H/sub 2/O molecule and the vacant metal site. The activation energy for reaction 1 increases in the order Ru/Al/sub 2/O/sub 3/ < Rh/Al/sub 2/O/sub 3/ < Ir/Al/sub 2/O/sub 3/ < Pt/Al/sub 2/O/sub 3/, whereas for reaction 2 the activation energy decreases in the order Ru/Al/sub 2/O/sub 3/ > Rh/Al/sub 2/O/sub 3/ > Ir/Al/sub 2/O/sub 3/. The preexponential factors of the rate constant for both reactions 1 and 2 do not vary significantly from one catalyst to another, although the value for reaction 1 is about 10/sup 4/ times smaller than that for reaction 2. The experimental results have been satisfactorily explained with the transition-state theory coupled with the above-mentioned reaction mechanism.},
doi = {10.1021/j150621a022},
url = {https://www.osti.gov/biblio/6071830}, journal = {J. Phys. Chem.; (United States)},
number = ,
volume = 85:21,
place = {United States},
year = {1981},
month = {10}
}