Applied Catalysis B: Environmental, Vol.123, 134-140, 2012
Selective catalytic reduction of NO on single site FeSiBEA zeolite catalyst: Influence of the C-1 and C-2 reducing agents on the catalytic properties
FeSiBEA zeolite with 0.8 Fe wt% is prepared in acidic condition (pH 2.5) by a two-step postsynthesis method which allows to incorporate iron into framework of zeolite as mononuclear distorted tetrahedral Fe(III) species, as evidenced by XRD, diffuse reflectance UV-vis and X-ray absorption spectroscopy. The single site FeSiBEA catalyst with isolated and framework Fe centres is active in SCR of NO process with C-2 (ethanol and ethylene) reducing agents, with selectivity towards N-2 exceeding 90% in the broad temperature range from 573 to 723 K for maximum NO conversion about 50 and 30% at 573 K for ethanol and ethylene respectively. In contrast, this catalyst is much less active with C-1 (methanol and methane) reducing agents, with maximum selectivity towards N-2 not exceeding 65% with methanol and 10% with methane for maximum NO conversion of 10 and 23% respectively. The low activity in CH4-SCR of NO on Fe(0.8)SiBEA catalyst containing only isolated mononuclear distorted tetrahedral Fe(III) species in the framework zeolite could be explained by high energy of C-H bond, which should be broken to activate methane molecule. (C) 2012 Elsevier B.V. All rights reserved.