Fig. 6. In situ spectroscopy of a Cu-CHA catalyst (Si/Al = 15; Cu/Al = 0.5) during NO/NH3 interaction at 50 °C (grey thin and blue thick lines: intermediates and final state, respectively) after equilibration in NO/O2 (red thick curves): (a) infrared; (b) DR UV-Vis; (c) magnitudes of FT-EXAFS spectra. (d) Structural model of a framework coordinated chelating bidentate Cu-nitrate and DFT optimized structure of the mobile mixed-ligand [Cu2+(NH3)3(NO3)]+ complex in the chabazite cage. Colour code: green, Cu; yellow, Si; brown, Al; red, O; blue, N; white, H. Adapted from ref. 97 with permission from John Wiley and Sons, copyright 2019.
