SEARCH Articles Figures Tables Ixical density of states on the clean metal surface at the Fermi level and IR stretch frequency of CO adsorbed on the same surfaces. For samples of Pl zeolite with different zeolite acidities, the clean metal-surface Ef LDOS was found from curves as in 1 ig. 57. Next, CO was adsorbed on these same samples, and the stretch frequency was measured as a function of coverage. The value plotted here is an extrapolation to zero coverage. This plot indicates that the C-O intramolecular bond after chemisorption will be weaker if the initial clean-surface LDOS is higher. [Publishers Imprint]