Spectroscopic Definition of a Highly Reactive Site in Cu-CHA for Selective Methane Oxidation: Tuning a Mono-μ-Oxo Dicopper(II) Active Site for Reactivity.

ABSTRACT: Using UV-vis and resonance Raman spectroscopy, we identify a [Cu₂O]²⁺ active site in O₂ and N₂O activated Cu-CHA that reacts with methane to form methanol at low temperature. The Cu-O-Cu angle (120°) is smaller than that for the [Cu₂O]²⁺ core on Cu-MFI (140°), and its coordination geometry to the zeolite lattice is different. Site-selective kinetics obtained by operando UV-vis show that the [Cu₂O]²⁺ core on Cu-CHA is more reactive than the [Cu₂O]²⁺ site in Cu-MFI. From DFT calculations, we find that the increased reactivity of Cu-CHA is a direct reflection of the strong [Cu₂OH]²⁺ bond formed along the H atom abstraction reaction coordinate. A systematic evalua

SUBMITTER: Rhoda HM 

PROVIDER: S-EPMC9112660 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature