The role of Bronstead acidity in poisoning the SCR-urea reaction over FeZSM-5 catalysts

Sullivan, James A.; Keane, Orla

doi:10.1016/j.apcatb.2005.06.001

Cited by 34 publications

(19 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the two catalysts were prepared by exactly the same procedure, the Fe loading of Fe-NaZ (1.62 wt%) was higher than that of Fe-HZ (1.27 wt%). Similar results have been reported and explained to be caused by the fact that the change in solution pH during the ion exchange process might be different for different precursors [9]. The residual Na content in Fe-NaZ was 0.61 wt%.…”

Section: Catalyst Compositionsupporting

confidence: 76%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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.

show abstract

Section: Catalyst Compositionsupporting

confidence: 76%

“…Fe-ZSM-5 prepared from a Na-ZSM-5 precursor showed lower NO conversion in the NH3-SCR reaction compared with those prepared from H + or NH4 + forms [9,10]. Pieterse et al [11] pointed out that the removal of framework aluminium by steam-dealumination should be slowed in Fe-ZSM-5 owing to the replacement of protons with sodium.…”

Section: Introductionmentioning

confidence: 99%

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

View full text Add to dashboard Cite

show abstract

“…However, concerns about the potential toxicity of vanadium oxide is opposed to its use and in the near future non-toxic materials will have to be employed [3]. Recently, Fe-ZSM5 received much attention as such a non-poisonous material, which proved to be highly active for the SCR reaction (see for example [4][5][6][7][8][9]). …”

Section: Thermo-hydrolysis Of Ureamentioning

confidence: 99%

Investigation of HNCO adsorption and hydrolysis on Fe-ZSM5

et al. 2007

View full text Add to dashboard Cite

At 150°C, HNCO adsorbs dissociatively on Fe-ZSM5 producing principally isocyanate species (-NCO) adsorbed on Al and Fe sites. In the presence of water the hydrolysis of the -NCO groups to NH 3 was observed. Comparison of the DRIFT results with measurements of the catalytic activity of coated cordierite monoliths suggests that -NCO groups are likely intermediate species in the hydrolysis of HNCO over Fe-ZSM5.

show abstract

“…Na and H form zeolites were usually used as precursors for preparation of the catalysts, and the activity of the zeolite for HC-SCR was reported to be strongly affected by the counter ions (H + or Na + ) in zeolites. For instance, it was reported that Ag-NaZSM-5 catalyst is more active than Ag-HZSM-5 for the selective catalytic reduction of NO by methane (CH 4 -SCR) at 450°C [6], and that Fe-ZSM-5 catalyst prepared from Na-ZSM-5 is far more active than that prepared from NH 4 -ZSM-5 for selective catalytic reduction of NO by urea [7]. Similarly, high activity for the selective catalytic reduction of NO by propene (C 3 H 6 -SCR) on Ce-NaZSM-5 [8,9] and for CH 4 -SCR on Pt-Co-NaFER washcoated cordierite monolith [10] was obtained.…”

Section: Introductionmentioning

confidence: 99%

Effect of Sodium in Ferrierite on Selective Catalytic Reduction of NO by Acetylene

et al. 2008

View full text Add to dashboard Cite

Influence of sodium in ferrierite (HFER) zeolite on selective catalytic reduction of NO by acetylene (C 2 H 2 -SCR) was investigated. NO x -TPD and FT-IR indicated that small amount of sodium exchanged into the proton-form zeolite with an exchange level of about 11.8% is beneficial for the title reaction by accelerating active nitrate species formation on catalyst surface from NO 2 and by suppressing the reductant combustion. Nevertheless, no further improved catalytic performance in C 2 H 2 -SCR could be observed by a larger amount of sodium exchanged into HFER due to some inactive nitrate species formed on the zeolite. Instead, activity of the zeolite for C 2 H 2 -SCR was drastically reduced, since the capacity of the zeolite for catalyzing NO oxidation and accelerating active NO + species formation was remarkably depressed.

show abstract

The role of Bronstead acidity in poisoning the SCR-urea reaction over FeZSM-5 catalysts

Cited by 34 publications

References 16 publications

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

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

Investigation of HNCO adsorption and hydrolysis on Fe-ZSM5

Effect of Sodium in Ferrierite on Selective Catalytic Reduction of NO by Acetylene

Contact Info

Product

Resources

About