The effect of adsorbed noble gas atoms on vibrational relaxation of hydroxyl group in zeolite

Abstract

By means of tunable infrared pump–probe experiment, vibrational relaxation rates (v=1→0) of OH stretching mode of Bro/nsted acidic hydroxyl groups in a mordenite zeolite, which were interacting with noble gases (He, Ar, Kr, or Xe), were measured. The population lifetime, T1, decreased with the increase of the interaction with noble gases, e.g., 170 ps and 58 ps for isolated hydroxyl groups and ones interacting with Xe, respectively. Using a simple linear chain model, the mechanism for the enhancement of the relaxation rate was studied.