The mechanism and kinetics of methane formation by decomposition of methanol on a Ni/SiO sub 2 catalyst

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90356-4· OSTI ID:6355524

de Bokx, P K; Balkenende, A R; Geus, J W ^[1]

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1. Univ. of Utrecht (Netherlands)

The rate of methane formation by decomposition of methanol is studied at temperatures between 473 and 583 K and methanol pressures between 0.2 and 10.4 kPa. Coverages of adsorbed species are measured using temperature-programmed hydrogenation (TPH), temperature-programmed desorption (TPD), and magnetic measurements. The reaction system can be adequately described assuming the decomposition of methanol to proceed in two steps, viz. a decomposition into CO and H{sub 2} followed by methanation of CO. The former reaction is much more rapid than the latter. Assuming CH hydrogenation to be rate-determining, the rate of methane formation could be described by the LHHW rate equation TOF = 1.2 {times} 10{sup 5}e{sup {minus}68/RT}p{sup 1.5}/(1 + 1.8 {times} 10{sup {minus}1}e{sup 15/RT}p{sup 0.5} + 3.1 {times} 10{sup {minus}16}e{sup 144/RT}p){sup 2}. TOF is the turnover frequency in s{sup {minus}1}, p is the methanol pressure in kPa, T is the temperature in K, and R = 8.314 {times} 10{sup {minus}3} kJ mol{sup {minus}1} K{sup {minus}1}. Coverages of adsorbed species predicted by this equation differ strongly from results obtained by measurements of total surface coverages using TPH, TPD, and magnetic measurements. This has been interpreted as an indication that the number of surface sites actively participating in the methanation reaction composes only a small fraction of the total number sites.

• OSTI ID: 6355524
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 117:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
ALCOHOLS
ALKANES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CONTROL
DECOMPOSITION
DESORPTION
ELEMENTS
EQUATIONS
HIGH TEMPERATURE
HYDROCARBONS
HYDROGEN
HYDROGENATION
HYDROXY COMPOUNDS
KINETIC EQUATIONS
KINETICS
MAGNETIC PROPERTIES
METALS
METHANATION
METHANE
METHANOL
NICKEL
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REACTION KINETICS
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE CONTROL
TRANSITION ELEMENTS