A vibrational overtone study of C–O bond weakening on potassium‐precovered ruthenium

Electron energy loss overtone spectroscopy is used to examine the C–O potential wells of carbon monoxide adsorbed on clean and potassium precovered Ru(001). While the C–O bond of CO adsorbed on the clean surface is found to be quite harmonic (ωeXe=18 cm−1), C–O bonds of CO coadsorbed with two different coverages of potassium exhibit highly anharmonic potential wells (ωeXe=70 cm−1, 95 cm−1).  Estimates of CO dissociation energies based on overtone frequencies indicate severely weakened CO bonds in agreement with 13C18O, 12C16O isotope scrambling thermal desorption results.