Selective catalytic reduction of NO by ammonia over Fe-ZSM-5 catalysts

Ma, Aiyuan; Grünert, Wolfgang

doi:10.1039/a807490i

Cited by 137 publications

(102 citation statements)

References 7 publications

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“…A similar performance has been achieved when using n-butane or propane [3]. Furthermore, high activity on Fe/ZSM5 obtained through CVD of FeCl 3 has been claimed also for the conventional selective catalytic reduction of NO using ammonia [4][5][6] and for the catalytic decomposition of N 2 O [7].…”

Section: Introductionsupporting

confidence: 50%

“…Iron loaded zeolites have recently attracted renewed attention due to their outstanding catalytic properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. In particular, over-exchanged Fe/ZSM5 (Fe/Al molar ratio > 0.5) obtained through the chemical vapor deposition (CVD) of anhydrous iron trichloride has been reported to be very efficient in the selective catalytic reduction of nitrogen oxides using HydroCarbons (HC-SCR).…”

Section: Introductionmentioning

confidence: 99%

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Evolution of Fe species during the synthesis of over-exchanged Fe/ZSM5 obtained by chemical vapor deposition of FeCl3

Battiston

Bitter

Groot

et al. 2003

Journal of Catalysis

163

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The evolution of iron in over-exchanged Fe/ZSM5 prepared via chemical vapor deposition of FeCl 3 was studied at each stage of the synthesis. Different characterization techniques (EXAFS, HR-XANES, 57 Fe Mössbauer spectroscopy, 27 Al NMR, EELS, HR-TEM, XRD, N 2 physisorption, and FTIR spectroscopy) were applied in order to correlate the changes occurring in the local environment of the Fe atoms with migration and aggregation phenomena of iron at micro-and macroscopic scale. Mononuclear isolated Fe-species are formed upon FeCl 3 sublimation, which are transformed into binuclear Fe-complexes during washing. During calcination, iron detached from the Brønsted sites migrates to the external surface of the zeolite, finally leading to significant agglomeration. Nevertheless, agglomeration of Fe can be strongly suppressed by adequately tuning the conditions of the calcination.  2002 Elsevier Science (USA). All rights reserved.

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Section: Introductionsupporting

confidence: 50%

Section: Introductionmentioning

confidence: 99%

Evolution of Fe species during the synthesis of over-exchanged Fe/ZSM5 obtained by chemical vapor deposition of FeCl3

Battiston

Bitter

Groot

et al. 2003

Journal of Catalysis

163

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“…The impact of SO2 on the SCR activity of Fe-ZSM-5 was different at low and high temperatures, in agreement with previous studies [31][32][33]. Long et al [33] suggested that the formation of surface iron sulfate on Fe-ZSM-5 increased the surface acidity of the catalyst and resulted in enhancement of its high temperature activity.…”

Section: Discussionsupporting

confidence: 81%

The effect of Fe species distribution and acidity of Fe-ZSM-5 on the hydrothermal stability and SO2 and hydrocarbons durability in NH3-SCR reaction

Shi

Xie

2015

Chinese Journal of Catalysis

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Fe-exchanged ZSM-5 catalysts prepared from Na ＋ and H ＋ forms of ZSM-5 were evaluated for the selective catalytic reduction of NOx by NH3 (NH3-SCR). Fe-H-ZSM-5 showed higher SCR activity than Fe-Na-ZSM-5 both when fresh and after hydrothermal aging at 750 °C in 5% H2O/air. The Fe species distribution and acidity of Fe-H-ZSM-5 and Fe-Na-ZSM-5 were found to be different. The dealumination of the zeolite framework of Fe-H-ZSM-5 during hydrothermal aging was found to be more severe compared with that of Fe-Na-ZSM-5. The durability of Fe-H-ZSM-5 and Fe-Na-ZSM-5 in NH3-SCR was compared using SO2 tolerance and hydrocarbon resistance experiments. The effect of water and SO2 on the activity of the two catalysts was similar, such that their activity decreased at low temperatures and increased at high temperatures. Fe-Na-ZSM-5 showed better propene resistance than Fe-H-ZSM-5. The SO2 and propene poisoning of the two Fe-ZSM-5 catalysts were found to be reversible.

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“…Fe exchanged zeolite catalysts usually show good SCR activity in the high temperature range with remarkable H 2 O and SO 2 durability, such as Fe-ZSM-5 by Ma and Gru¨nert 10 and Fe-Ce-ZSM-5 by Carja et al 11 Other Fe-based catalysts are mainly Fe 2 O 3 loaded types such as Fe 2 O 3 -TiO 2 by Kato et al 12 and Fe 2 O 3 -WO 3 /ZrO 2 by Apostolescu et al 13 with excellent SCR activity and H 2 O/SO 2 durability in the medium temperature range. Based on the idea of combining the predominant SCR activity, thermal stability and N 2 selectivity of Fe-based catalysts and the excellent SO 2 durability of TiO 2 , here we present a novel non-toxic catalyst using an iron titanate crystallite as the active component with a broad operation window in the medium temperature range (200-400 1C) under relatively high space velocities.…”

mentioning

confidence: 99%

Novel iron titanate catalyst for the selective catalytic reduction of NO with NH3 in the medium temperature range

2008

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An iron titanate catalyst with a crystallite phase, prepared by a co-precipitation method, showed excellent activity, stability, selectivity and SO 2 /H 2 O durability in the selective catalytic reduction of NO with NH 3 in the medium temperature range.Nitrogen oxides (NO x ) have become a major source of air pollution which can result in photochemical smog, acid rain and ozone depletion and have strong respiratory toxicity endangering human health.1 Stringent environmental legislation has been made worldwide to reduce NO x emitted from mobile and stationary resources including vehicles and coal-fired power plants. Selective catalytic reduction of NO with NH 3 (NH 3 -SCR) is an effective and economical method to remove NO and nowadays the most widely used catalyst system is V 2 O 5 -WO 3 /TiO 2 or V 2 O 5 -MoO 3 /TiO 2 with a relatively narrow temperature window of 350-400 1C.2 The problems of this system are as follows: the low N 2 selectivity in the high temperature range because of N 2 O formation and NH 3 overoxidation; the toxicity of vanadium pentoxide to the environment; and high conversion of SO 2 to SO 3 with increasing vanadium amounts, which can result in catalyst deactivation. 13 with excellent SCR activity and H 2 O/SO 2 durability in the medium temperature range. Based on the idea of combining the predominant SCR activity, thermal stability and N 2 selectivity of Fe-based catalysts and the excellent SO 2 durability of TiO 2 , here we present a novel non-toxic catalyst using an iron titanate crystallite as the active component with a broad operation window in the medium temperature range (200-400 1C) under relatively high space velocities. NO conversion at 300 1C remaining at 100% in the presence of 10% H 2 O and (or) 100 ppm SO 2 makes this catalyst a potential candidate for industrial applications.The iron titanate catalysts were prepared by the conventional co-precipitation method using Fe(NO 3 ) 3 Á9H 2 O and Ti(SO 4 ) 2 as precursors (Fe : Ti ¼ 1 : 1 in molar ratio) and 25 wt% NH 3 ÁH 2 O as precipitator with subsequent filtration, washing, and drying at 100 1C overnight and calcination at 400, 500, 600, 700 1C for 6 h, respectively (signified by Fe x TiO y -400, 500, 600, 700 1C). Catalysts sieved with 20-40 mesh were used in the activity test experiments and the reaction conditions were as follows: 0.6 ml sample, 500 ppm NO, 500 ppm NH 3 , 5% O 2 , 100 ppm SO 2 (when used), 10% H 2 O (when used), balance N 2 , 500 ml min À1 total flow rate and gas hourly space velocity (GHSV) ¼ 50 000 h À1. The water vapor was injected with an accurate syringe pump equipped with an evaporator which was heated to 300 1C. The tubing of the activity test system was heated to 120 1C to avoid deposition of ammonium salts and water droplets. The effluent gas, including NO, NH 3 , N 2 O and NO 2 dried using CaSO 4 was continuously analyzed by an FTIR spectrometer (Thermo Nicolet Corporation Nexus 670, OMNIC Quantpad software) equipped with a heated, low volume multiple-path gas cell (2 m). The spectra were collected...

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Selective catalytic reduction of NO by ammonia over Fe-ZSM-5 catalysts

Cited by 137 publications

References 7 publications

Evolution of Fe species during the synthesis of over-exchanged Fe/ZSM5 obtained by chemical vapor deposition of FeCl3

Evolution of Fe species during the synthesis of over-exchanged Fe/ZSM5 obtained by chemical vapor deposition of FeCl3

The effect of Fe species distribution and acidity of Fe-ZSM-5 on the hydrothermal stability and SO2 and hydrocarbons durability in NH3-SCR reaction

Novel iron titanate catalyst for the selective catalytic reduction of NO with NH3 in the medium temperature range

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