Fe-Cu-SSZ-13 catalysts were prepared by aqueous solution ion-exchange method based on the one-pot synthesized Cu-SSZ-13. The catalysts were applied to the selective catalytic reduction (SCR) of NO with NH3 and characterized by the means of XRD, UV-Vis, EPR, XPS, NH3-TPD, and so on. The selected Fe-Cu-SSZ-13-1 catalyst exhibited the high NO conversion (>90%) in the wide temperature range (225-625 degrees C), which also showed good N-2 selectivity and excellent hydrothermal stability. The results of XPS showed that the Cu and Fe species were in the internal and outer parts of the SSZ-13 crystals, respectively. The results of UV-Vis and EPR indicated that the monomeric Cu2+ ions coordinated to three oxygen atoms on the six-ring sites and Fe monomers are the real active species in the NH3-SCR reaction. Furthermore, the influence of intracrystalline mass-transfer limitations on the Fe-Cu-SSZ-13 catalysts is related to the location of active species in the SSZ-13 crystals. (c) 2015 American Institute of Chemical Engineers