Effect of the Electronic State and Copper Localization in ZSM-5 Pores on Performance in NO Selective Catalytic Reduction by Propane Full article
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Applied Catalysis B: Environmental
ISSN: 0926-3373 , E-ISSN: 1873-3883 |
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| Output data | Year: 2011, Volume: 103, Number: 1-2, Pages: 1-10 Pages count : 10 DOI: 10.1016/j.apcatb.2010.12.046 | ||
| Tags | Extraframework aluminum, HZSM-5, Localization, Modifying copper species, NO removal, Post-synthetic modification | ||
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Abstract:
This study was devoted to determination of localization of the individual copper species in the pores of ZSM-5 zeolite after post-synthetic zeolite modification by incipient wetness impregnation with CuCl2 solution followed by hydrolytic polycondensation of the ions in the pores. A series of Cu(n)ZSM-5 samples, where n is the copper concentration varied from 0.5 to 5.0 wt.%, were synthesized using this method. A commercial HZSM-5 zeolite having Si/Al = 17 was used for the synthesis of the catalysts. After modification the Cu(n)ZSM-5 samples were dried and calcined in air at 110 and 450 °C, respectively. The samples were studied by UV–vis–NIR DR spectroscopy, XRD and by measuring and processing the low-temperature (77 K) adsorption of nitrogen and hydrogen. It was shown for the first time that at the concentration of 1.0 wt.% or lower copper was localized in the form of isolated Cu2+Oh cations in the ion-exchange positions in the zeolite micro- and mesopores as well as on oxygen complexes of extraframework aluminum in thin mesopores with D < 3.2 nm in the form of superficial spinel-like structures in octahedral oxygen coordination Cu2+Oh. At the copper concentration above 1.0 wt.% linear associates of weakly bound Cu2+Oh ions with unusual orbital ordering were formed in addition to the two forms discussed above. These associates existing in the forms of one- and two-dimensional nanohydroxocompounds were localized partially in the zeolite micropores but mostly in thin mesopores.
The effect of the individual copper species on the catalytic properties of Cu(n)ZSM-5 samples in selective catalytic reduction of NO by propane was also studied. It was found that isolated Cu2+Oh cations in the ion-exchange positions and Cu2+Oh cations localized on the oxygen complexes of extraframework aluminum had the highest catalytic activity in NO SCR by propane. The weakly bound linear associates of Cu2+Oh ions had lower catalytic activity, compared with isolated Cu2+Oh ions. When their amount was high, they caused steric hindrance for contact of the reagents with the more active sites. The Cu2+Oh ion associates were found to transform to nanodispersed Cu2(OH)3Cl during catalytic experiments.
Cite:
Krivoruchko O.P.
, Larina T.V.
, Shutilov R.A.
, Gavrilov V.Y.
, Yashnik S.A.
, Sazonov V.A.
, Molina I.Y.
, Ismagilov Z.R.
Effect of the Electronic State and Copper Localization in ZSM-5 Pores on Performance in NO Selective Catalytic Reduction by Propane
Applied Catalysis B: Environmental. 2011. V.103. N1-2. P.1-10. DOI: 10.1016/j.apcatb.2010.12.046 WOS Scopus РИНЦ ANCAN OpenAlex
Effect of the Electronic State and Copper Localization in ZSM-5 Pores on Performance in NO Selective Catalytic Reduction by Propane
Applied Catalysis B: Environmental. 2011. V.103. N1-2. P.1-10. DOI: 10.1016/j.apcatb.2010.12.046 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
| Submitted: | Oct 14, 2010 |
| Accepted: | Dec 18, 2010 |
| Published online: | Jan 6, 2011 |
| Published print: | Mar 1, 2011 |
Identifiers:
| Web of science: | WOS:000288884500001 |
| Scopus: | 2-s2.0-79951941906 |
| Elibrary: | 16684255 |
| Chemical Abstracts: | 2011:252928 |
| Chemical Abstracts (print): | 154:467342 |
| OpenAlex: | W1976815912 |