XAFS study of Cu-I-Y and Cu-II-Y interacting with CO and NO

We report a study of the local copper environment in Cu-I-Y prepared by gas phase reaction of H-Y with CuCl and in Cu-II-Y prepared by conventional ion exchange with aqueous cupric salt. For the Cu-I-Y sample, the effect of the interaction with CO and NO will also been reported. XANES, W-Vis and IR (NO dosed at 77 K) techniques prove that the copper species in the prepared samples have the desired oxidation state. Reduction of Cu-I-Y with CO leads to the formation of small copper clusters well identified by EXAFS, XANES and UV-Vis spectroscopies, while interaction with NO partially oxydate Cu-I to Cu-II. For both as prepared Cu-I-Y and Cu-II-Y samples EXAFS does not observe first shell Cu-Cu bond lengths, so excluding the presence of ''so called'' Cu-dimers in zeolites prepared following our methods.