| Abstract
| - The interaction of CO with extraframework Li+ ions coordinated in ZSM-5 and FER zeolites with differentcompositions is investigated by FTIR spectroscopy, and the correlation between Li+ coordination, stability ofCO adsorption complexes, and νCO frequencies is discussed in terms of the theoretical investigation of thestability and vibrational dynamics of CO adsorption complexes. Differences in IR spectra of adsorbed COdue to the following effects were considered: (i) various Si/Al ratios, (ii) differences in zeolite topology, (iii)temperature, and (iv) the effect of a co-cation on relative stability and metal cation site preferences. Thecorrelation between Li+ coordination and νCO frequencies of CO adsorption complexes discussed for Li zeolitesis extrapolated to mesoporous Li−(Al)MCM-41 materials. The features in the IR spectra of CO/Li−(Al)MCM-41 are assigned to CO adsorption complexes formed on top of five- and six-membered rings on thesurface of a channel wall. The spectra of CO/Li−ZSM-5 with different Si/Al ratios and various ion exchangelevels bring evidence on the nonstatistical distribution of aluminum in the framework and on the preferenceof Li+ ions for channel-wall sites.
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