ASSIGNMENT OF THE D-ORBITALS INVOLVED IN THE CHEMISORPTION BOND OF CO ON RE(0001)

Angular resolved photoelectron spectra and thermal desorption spectra show that CO is molecularly adsorbed at room temperature on the Re(0001) surface. The observed d-band photoemission peaks are individually reduced in intensity after CO chemisorption. This behavior is discussed in terms of a bonding model. Structures in the photoelectron spectra which are most strongly attenuated are mainly derived from atomic orbitals of symmetry dxz and dyz. Thus these orbitals are involved in the chemisorption bond. This interpretation of the photoemission data together with the observation of an increase in work function and a diffuse LEED pattern leads to the conclusion that CO is bonded in bridge or hollow sites up to the saturation coverage of the α2 state in the thermal desorption spectra. © 1979.