ADSORPTION AND DECOMPOSITION OF NITROUS-OXIDE ON ZIRCONIA NANOPARTICLES

FT-IR spectroscopy has been used to study the adsorption and decomposition of nitrous oxide on zirconia nanoparticles. The room temperature IR spectrum of adsorbed nitrous oxide is characterized by two intense absorption bands corresponding to the symmetric stretch and asymmetric stretch that are shifted by over 45 and 17 cm(-1) respectively, from the gas phase values. Results from experiments as a function of sample pretreatment and site blocker adsorption indicate that nitrous oxide adsorbs on Zr4+ sites at room temperature and the mode of attachment is through the oxygen atom. Dissociation of nitrous oxide over zirconia begins at temperatures above 350 degrees C. The data suggest that Lewis acid sites (Zr4+) are the active sites for nitrous oxide decomposition and the room temperature adsorbed species is a precursor to nitrous oxide decomposition.