SBA-15 modified with iron by various methods was tested as catalyst of the DeNOx process. Two methods were used for deposition of iron: (i) molecular designed dispersion method to introduce Fe in the form of monomeric cations and (ii) ion-exchange of iron acetate oligocations, [Fe3O(OAc)(6)center dot AcOH center dot 2H2O](+), for SBA-15 modified with propylsulfonic groups to introduce aggregated iron oxide species. The obtained samples were characterized with respect to: textural parameters (low-temperature N-2 adsorption), structure (XRD, TEM), efficiency of surface species anchoring (DRIFT, FTIR-PAS, TG-DTG and elemental analysis), form and aggregation of deposited iron species (Mossbauer spectroscopy, UV-vis-DRS, H-2-TPR, CO-FTIR), distribution of iron oxide species in the samples (TEM-EDX). SBA-15 modified with iron was found to be effective catalysts of selective reduction of NO with ammonia. It was suggested that iron deposited in the form of aggregated FeOx species presents higher catalytic activity in the studied process comparing to monomeric Fe3+ cations. (C) 2016 Elsevier Ltd. All rights reserved.