Mechanism And Selectivity In The Epoxidation Of Ethylene Over Silver: The Results Of Single Crystal Measurements

The silver-catalysed oxidation of ethylene has been examined on the (III) face of a single crystal by a combination of electron spectroscopy and kinetic measurements at pressures of up to 50 Torr. The necessary and sufficient conditions for ethylene oxide formation are established, reaction intermediates are identified, kinetic isotope effects are observed and the role of Cs in modifying reaction selectivity is examined. It is shown that surface alkali exhibits opposite effects on the reactions which lead to the further oxidation of ethylene oxide and on the direct combustion of ethylene. © 1984.

Anomalous n-type electrical behaviour of Pd-contacted CNTFET fabricated on small-diameter nanotube.

A Pd-contacted dopant-free CNTFET with small-diameter (0.57 nm) carbon nanotube showing an anomalous n-type electrical characteristic is reported for the first time. This observed behaviour is attributed to a carbon nanotube work function higher than (or close to) palladium as well as a large hole-to-electron effective mass ratio of approximately 2.5 predicted by hybridization in small-diameter nanotubes. A variation of the conduction type with temperature is also observed and is attributed to an increase of the palladium work function and decrease of the CNT work function with increasing temperature.