conditioning process [35]. The XRD pattern of the silver-supported chabazite samples (not-shown) did not display the corresponding silver diffraction peaks. This result is similar to that reported in Ref. [21], where no silver diffraction peaks are observed in the XRD patterns of silver supported chabazite samples treated in oxidizing environment. The lack of silver diffraction signals in the patterns of those samples was explained in terms of the reduced size of the silver nanoparticles which must be smaller than the limit detection of XRD.