Fig. 7. (a) Low temperature (∼–160 °C) normalized FTIR spectra of N2 dosed at increasing equilibrium pressure (from 10–2 to 5 Torr) on vacuum-activated Cu-CHA catalysts with different compositions, indicated by (Cu/Al; Si/Al) labels. Black, red and light grey curves refer to the lowest, highest and intermediate N2 coverage, respectively. (b) Normalized areas of the N2/Cu(i) IR peaks measured at the highest coverage, including normalized areas of LF and HF components calculated by spectral deconvolution.
