Isotope effect and rate-determining step of the CO{sub 2}-reforming of methane over supported Ni catalyst
- National Industrial Research Inst. of Nagoya (Japan)
The authors have developed pulse surface reaction rate analysis (PSRA) for investigating the kinetics of the CO{sub 2}-reforming of methane. This rate analysis has enabled them to determine the reactivity of intermediate species with no information about the number of active sites. The following findings were revealed for CO{sub 2}-reforming over supported Ni catalysts: (1) Two steps are responsible for H{sub 2} production, i.e., dissociative adsorption of CH{sub 4} to produce (4 {minus} x)/2H{sub 2} and CH{sub x}, and subsequent production of x/2H{sub 2} together with CO by the surface reaction between CH{sub x} species and atomic oxygen. (2) The number of hydrogen atoms involved in CH{sub x} is dependent on the supports, although the reactivity is not correlated with the number of hydrogen atoms. (3) An isotope effect on the reaction of adsorbed hydrocarbon species with atomic oxygen is observed; the first-order rate constant for this reaction is 1.45 times larger for CH{sub 4} than for CD{sub 4} on Ni/Al{sub 2}O{sub 3} at 723 K. (4) The surface reaction between CH{sub x} and O to produce CO and H{sub 2} is considered the rate-determining step. In this paper, ab initio molecular orbital calculation of the surface reaction between CH{sub x} and O to give CO and H{sub 2} was carried out. The theoretical isotope effect was estimated from the transition-state theory and compared with the experimental one.
- OSTI ID:
- 316304
- Journal Information:
- Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 1 Vol. 180; ISSN 0021-9517; ISSN JCTLA5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Kinetics, isotope effects, and mechanism for the hydrogenation of carbon monoxide on supported nickel catalysts
Kinetics, isotope effects, and mechanism of the hydrogenation of carbon monoxide on supported palladium catalyst
Kinetics of the steam reforming of methane with iron, nickel, and iron-nickel alloys as catalysts
Journal Article
·
Thu Jul 08 00:00:00 EDT 1982
· J. Phys. Chem.; (United States)
·
OSTI ID:6629208
Kinetics, isotope effects, and mechanism of the hydrogenation of carbon monoxide on supported palladium catalyst
Journal Article
·
Thu Sep 15 00:00:00 EDT 1983
· J. Phys. Chem.; (United States)
·
OSTI ID:5597090
Kinetics of the steam reforming of methane with iron, nickel, and iron-nickel alloys as catalysts
Journal Article
·
Mon Nov 30 23:00:00 EST 1981
· J. Catal.; (United States)
·
OSTI ID:5600311