Copper Pairing in the Mordenite Framework as a Function of the Cu^I /Cu^II Speciation.

ABSTRACT: A series of gas-phase reactants is used to treat a Cu-exchanged mordenite zeolite with the aim of studying the influence of the reaction environment on the formation of Cu pairs. The rearrangement of Cu ions to form multimeric sites as a function of their oxidation state was probed by X-ray absorption spectroscopy (XAS) and also by applying advanced analysis through wavelet transform, a method able to specifically locate Cu-Cu interactions also in the presence of overlapping contributions from other scattering paths. The nature of the Cu-oxo species formed upon oxidation was further crosschecked by DFT-assisted fitting of the EXAFS data and by resonant Raman spectroscopy. Altogether, the Cu^I /Cu^II speciation clearly correlates with Cu proximity, with metal ion pairs quantitatively forming under an oxidative environment.

SUBMITTER: Deplano G 

PROVIDER: S-EPMC9298398 | biostudies-literature |

REPOSITORIES: biostudies-literature