Figure 6
Plot of seven NEXAFS (μ) scans referring to the Cu L2 and L3 edges acquired during the cooling ramp (from 135°C to 100°C) in the presence of CO for a Cu-exchanged CHA zeolite (Cu/Al = 0.5, Si/Al = 15; Cu 2.6 wt%: typical example of diluted absorbing element). It is evident from the graph that the classical background subtraction and normalization procedures typical of hard-XAS cannot be applied here because of low-edge absorption jumps and the non-linear background. |