Coexistence of atomic and molecular chemisorption states: H(2)/Pd(210).
A novel H(2) molecular adsorption state on metal surfaces has been detected by temperature-programmed desorption and electron energy loss spectroscopy experiments of the H(2)/Pd(210) system. The molecular nature of this state has been verified by isotope exchange experiments. This molecular state leads to a decrease of the surface work function while atomic hydrogen on Pd(210) causes an increase. Ab initio total-energy calculations have confirmed all experimental findings. Through these calculations the microscopic nature of this novel molecular adsorption state could be identified; it turns out that this state is stabilized by the presence of atomic hydrogen on the Pd(210) surface.
Schmidt
P K
PK
Institut für Chemie der Freien Universität Berlin, D-14195 Berlin-Dahlem, Germany.
Christmann
K
K
Kresse
G
G
Hafner
J
J
Lischka
M
M
Gross
A
A