Cover Feature: Evidence of Mixed‐Ligand Complexes in Cu−CHA by Reaction of Cu Nitrates with NO/NH 3 at Low Temperature (ChemCatChem 16/2019)

The Cover Feature depicts the chemistry taking place within the cages of the Cu‐exchanged chabazite zeolite, during the reaction of pre‐formed Cu II ‐nitrates with a NO/NH 3 flow at 50 °C. In their Full Paper, Gloria Berlier and co‐workers investigate the low temperature reactivity of Cu‐CHA towards the main reactants of the NH 3 ‐assisted Selective Catalytic Reduction, by in situ FTIR, Diffuse Reflectance UV‐Vis and XAS spectroscopies. Framework‐interacting Cu II ‐nitrates, formed by reaction with a diluted NO/O 2 mixture, are readily transformed by interaction with NH 3 (alone or in a NO/NH 3 mixture) into mixed‐ligand mobile [Cu II (NH 3 ) 3 (NO 3 )] + complexes. DFT calculations indicate that the modification of the nitrate ligand configuration from chelating bidentate to monodentate during this transformation is favored by the NH 3 solvation environment. More information can be found in the Full Paper by Chiara Negri et al. on page 3828 in Issue 16, 2019 (DOI: 10.1002/cctc.201900590).