IR spectra of zeolites recorded at liquid helium temperature

Lowering the temperature narrows IR bands and improves apparent spectral resolution of solids, We studied the spectra of. mordenite, mazzite, faujasite, TON (all of them of high Si/Al), silicalite, as well as two SiO2 materials (inesoporous MCM-41 and amorphous SiO2) at liquid helium temperature. IR spectra recorded at liquid helium temperature inform on crystlographically non-equivalent oxygen atoms in zeolite structure, and this knowledge is complementary to that obtained fro M Si-29 MAS NMR studies, which inform on crystalographically non-equivalent Si atoms. In the future the analysis of low temperature IR spectra call inform how various factors, Such as the presence of reactant molecules, call affect various oxygen atoms in zeolite framework.