Kinetics of the activated dissociative adsorption of methane on the low index planes of nickel single crystal surfaces

Journal Article · Sat Aug 15 00:00:00 EDT 1987 · J. Chem. Phys.; (United States)

OSTI ID:6368334

Beebe, Jr, T P; Goodman, D W; Kay, B D; Yates, Jr, J T

We have measured the kinetics of the methane decomposition reaction on Ni(111), Ni(100), and Ni(110) single crystal surfaces under the high incident flux conditions of 1 Torr methane. We find for these processes apparent activation energies of 12.6, 6.4, and 13.3 kcal mol/sup -1/, respectively. Initial methane sticking coefficients at 500 K vary with the Ni surface, but are all --10/sup -8/ to 10/sup -7/. The Ni(110) surface is the most active, followed by Ni(100) and Ni(111). A large (-- factor of 20) kinetic isotope effect is seen for CH/sub 4/ vs CD/sub 4/ on the Ni(100) surface, whereas none is seen on the Ni(110) surface. A comparison is made between measured thermal sticking coefficients and those calculated from the results of recent molecular beam experiments of CH/sub 4/ on Ni(111) and Ni(100) surfaces. Agreement of our results with the Ni(100) beam results is poor, whereas agreement with the Ni(111) beam results is very good. A comparison is also made between our results and rates of the catalytic steam reforming reaction of methane.

• Research Organization: Sandia National Laboratories, Albuquerque, New Mexico 87185
• OSTI ID: 6368334
• Journal Information: J. Chem. Phys.; (United States), Vol. 87:4
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
03 NATURAL GAS
METHANE
ADSORPTION
CHEMICAL REACTION KINETICS
DECOMPOSITION
NICKEL
SORPTIVE PROPERTIES
ACTIVATION ENERGY
CATALYSIS
ALKANES
CHEMICAL REACTIONS
ELEMENTS
ENERGY
HYDROCARBONS
KINETICS
METALS
ORGANIC COMPOUNDS
REACTION KINETICS
SORPTION
SURFACE PROPERTIES
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties
030400 - Natural Gas- Products & By-Products