AN EXPERIMENTAL-STUDY OF VIBRATIONAL ENHANCEMENT OF THE DISSOCIATIVE CHEMISORPTION OF ETHANE ON PT(111)

Measurements have been made of the initial sticking coefficient, S-0(d iss), Of ethane on a Pt(111) substrate which provide clear evidence fo r the enhancement of sticking of vibrationally excited molecules. An a nalysis of the results, based on an harmonic density-of-states calcula tion, suggests that combinations involving deformation vibrational mod es of the molecule are responsible for this enhancement.