Thermochemical-dependent Cu(I) siting and mobility in Cu-CHA revealed by XAS and quantum mechanical simulations

Cu mobility in Cu-zeolites is still an underrated factor in the description of their reactivity, in spite of multiple literature reports suggesting its relevance. Herein we provide a XAS-based description of the displacement of Cu(i) in chabazite upon exposure to different gas-phase ligands and/or thermal treatments. Two preferential sites are accessible to ions depending on the applied stimuli, namely thermodynamically favored in 6-membered rings and metastable in 8-membered rings. DFT-aided data interpretation fully supports the experimental findings, allowing an atomistic description of Cu(i) mobility under the explored conditions.