Methanolic C-0 bond activation on Pd(111): Coverage-dependent reaction. (Reannouncement with new availability information)

Technical Report · Thu Dec 31 04:00:00 EST 1992

OSTI ID:166857

Chen, J J; Winograd, N

The authors find that the previously reported methanolic C-O bond activation on Pd 111 to form adsorbed methyl and hydroxyl at 225 K occurs only for initial methanol coverages near 1 monolayer. At lower and higher coverages, methanol decomposes via the more traditional methoxy intermediate. Moreover, when methyl is formed, it is not observed to decompose until the temperature is raised to 400 K. This thermal behavior is quite unusual since CH3 has been observed to combine with H to desorb as CH4 below 300 K, dimerize to produce C2H6 below 200 K, or dehydrogenate to form CH2 and H below 200 K. In addition, the authors find that methyl undergoes sequential dehydrogenation as the temperature is increased to form CH2 at 400 K, CH at 500 K, and C at >500 K. They speculate that the coverage dependency is connected with the thermal stability of CH3 by a site-blocking mechanism, probably involving CO.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemistry
• OSTI ID: 166857
• Report Number(s): AD-A--250634/3/XAB; CNN: Contract N00014-91-J-1410
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
10 SYNTHETIC FUELS
ACTIVATION ENERGY
ADSORPTION
CATALYSIS
DECOMPOSITION
DEHYDROGENATION
FISCHER-TROPSCH SYNTHESIS
HYDROXYL RADICALS
METHANE
METHANOL
METHYL RADICALS
PALLADIUM