Coadsorption of ethylene and potassium on Pt(111). 1. Formation of a. pi. -bonded state of ethylene
High resolution electron energy spectroscopy (HREELS), temperature-programmed desorption (TPD), and ultraviolet photoelectron spectroscopy (UPS) have been combined to study the effect of preadsorbed potassium on the adsorption of ethylene on the platinum(111) single-crystal surface. Addition of potassium increases the relative amount of reversible ethylene adsorption at 100 K/. Upon coadsorption with potassium, the authors also observe a new low-temperature ethylene desorption state at 150 K, with E/sub d/ = 5-9 kcal mol/sup -1/, which is about one-half the binding energy of ethylene adsorbed on clean Pt(111). The origin of this new desorption state is the formation of a weakly interacting ethylene species, which is only slightly distorted from the gas-phase hybridization, as determined primarily by vibrational spectroscopy. An explanation is given for these effects in which the increased charge density at the platinum surface due to coadsorbed potassium inhibits the strong sigma-donation of adsorbed ethylene to platinum and greatly reduces the chemisorption bond strength.
- Research Organization:
- Univ. of Colorado, Boulder (USA)
- DOE Contract Number:
- FG02-86ER13473
- OSTI ID:
- 6668121
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 92:10
- Country of Publication:
- United States
- Language:
- English
Similar Records
Summary abstract: the coadsorption of CO and K on Rh(111): an HREELS, TPD, AES, and LEEd study
Bi adsorption and poisoning on Ni(100) surface as probed by CO chemisorption
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ETHYLENE
ADSORPTION
PLATINUM
SORPTIVE PROPERTIES
POTASSIUM
CHEMICAL BONDS
ENERGY-LOSS SPECTROSCOPY
EXPERIMENTAL DATA
PHOTOELECTRON SPECTROSCOPY
ULTRAVIOLET RADIATION
VIBRATIONAL STATES
ALKALI METALS
ALKENES
DATA
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY LEVELS
EXCITED STATES
HYDROCARBONS
INFORMATION
METALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PLATINUM METALS
RADIATIONS
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
TRANSITION ELEMENTS
400201* - Chemical & Physicochemical Properties