Characterization of Cu+ ions in CuHZSM-5 zeolites and CuSAPO-34 molecular sieve Cu+ laser-induced luminescence and 129Xe-NMR diagnosis

Lassoued, Abdelmajid; Deson, J.; Lalo, C.; Gédéon, A.; Fraissard, J.; Bı̂rjega, R.; Ganea, Rodica; Nenu, Cristina N.

doi:10.1016/s1387-1811(00)00333-4

Cited by 10 publications

(8 citation statements)

References 33 publications

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“…From two given values, the τ 1 lifetime is too short (order of magnitude) to be affected by the luminescence decay of Zn 2+ luminescence center and is likely to characterize the electron lifetime at a neighboring higher energetic level (or levels). 1,56 3. RESULTS AND DISCUSSION 3.1.…”

Section: Methodsmentioning

confidence: 99%

“…This suggests a multilevel model of the luminescence similar to the one suggested for Cu + centers. , Therefore, τ 2 is characterizing Zn 2+ luminescence center. From two given values, the τ 1 lifetime is too short (order of magnitude) to be affected by the luminescence decay of Zn 2+ luminescence center and is likely to characterize the electron lifetime at a neighboring higher energetic level (or levels). , …”

Section: Experimental Sectionmentioning

confidence: 99%

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Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy

et al. 2021

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A methodology for the analysis of the siting of Zn 2+ ions in extra-framework cationic sites of silicon-rich zeolite was developed and demonstrated on Zn-ferrierite samples (Si/Al 8.5, Zn/Al 0.04−0.33). This methodology is based on the FTIR spectroscopy of antisymmetric tetrahedral−octahedral−tetrahedral (T-O-T) vibrations of the zeolite framework perturbed by Zn 2+ ions, combined with a complementary approach based on Zn 2+ luminescence monitored by laser-induced timeresolved luminescence spectroscopy. Three vibration bands in the FTIR spectra of antisymmetric T-O-T vibrations of dehydrated zeolite reflect Zn 2+ ligation in three extra-framework cationic sites of ferrierite zeolite. The band at 935 cm −1 corresponds to Zn 2+ ions in the α-site of ferrierite, the band at 917 cm −1 correspondsto ions in β-site, and the band at 902 cm −1 correspondsto Zn 2+ ions in the γ-site. The extinction coefficient for quantitative analysis of Zn 2+ ions in cationic sites was estimated and exhibited the same value for Zn 2+ cations in all cationic sites, ε = 49.1 ± 3.8 cm•μmol −1 . In all Zn samples, Zn 2+ siting in the β-site prevails, while Zn 2+ ions in the γ-site are of low population or negligible. Time-resolved luminescence showed that bare Zn 2+ ions in the extra-framework cationic sites can be distinguished from Zn 2+ ions in ZnO by a decay time which is several magnitudes longer and a high sensitivity for quenching. The luminescence spectrum of Zn-ferrierites is composed of three bands at 545, 480, and 425 nm attributable to Zn 2+ ions in the α-, β-, and γ-site with luminescence coefficients (for semiquantitative analysis) ζ α = 10.1, ζ β = 9.4, and ζ γ = 8.8 mmol/g of Zn 2+ ions in the α-, β-, and γ-sites, respectively. The analysis of Zn ions in ferrierites showed that ZnH-ferrierites exclusively contain Zn 2+ ions in cationic sites. In the case of the ZnNa-FER sample with maximum Zn loading (Zn/Al 0.33), a small amount of Zn-oxo species can be formed.

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Section: Methodsmentioning

confidence: 99%

Section: Experimental Sectionmentioning

confidence: 99%

Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy

et al. 2021

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“…The stable isotope, 133Cs, was used. A zeolite‐containing absorbent sheet (1 cm) was immersed in 50 mL of 1 ppm Cs + aqueous solution (50 µg Cs + ), and was stirred for 2.5 h. The solution was then passed through a 0.20 µm membrane filter, and the Cs + concentration was measured by inductively coupled plasma mass spectrometry (ELANDRC II).…”

Section: Methodsmentioning

confidence: 99%

“…It is also found in Yonezawa, Yamagata prefecture and Yaita, Tochigi prefecture . Zeolite can be used as a molecular sieve, an adsorbant and for ion exchange . Its practical applications include drainage treatment, as fillers, soil conditioners and feed additives .…”

Section: Introductionmentioning

confidence: 99%

The removal of cesium ion with natural Itaya zeolite and the ion exchange characteristics

Endo

Yoshikawa

Muramatsu

et al. 2013

J of Chemical Tech & Biotech

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BACKGROUND: The large Itaya zeolite deposit in Yonezawa, Japan produces good quality, natural zeolite. Its properties as an adsorbent and a functional carrier were assessed and the ion exchange characteristics examined. Natural zeolite has a useful high cation exchange capacity, but has a disadvantage in scattering of the powder. In this study a nonwoven fabric containing zeolite was tested for the removal of cesium. RESULTS:The X-ray diffraction (XRD) peak pattern confirmed that Itaya zeolite is mainly clinoptilolite and contains some mordenite. Ion exchange selectivity of the natural zeolite was Ag + > Pb 2+ > Cu 2+ > Zn 2+ > Cd 2+ > Cr 3+ > Ni 2+ with almost 100% removal of Ag + and Pb 2+ ions.The cation exchange capacity (CEC) of Itaya zeolite was 131 cmol kg -1 . Low concentrations of Cs + were removed effectively from the solution with natural zeolite. Cesium ions were removed by ion exchange with potassium and sodium. Cs + was desorbed from the zeolite with ammonium salt solutions. Elution of Cs + was influenced by the coordination ability of counter anions. CONCLUSION: Satisfactory results were obtained using zeolite-containing nonwoven fabric for the removal of cesium ions.

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“…Since the pioneering work by Ito and Fraissard in 1981, 23 several groups reported that 129 Xe NMR chemical shifts strongly depend on types or valence of extraframework cations inside the X and Y zeolites. [31][32][33][34][35][36][37][38]50 In particular, interactions between the Xe atom and a d 10 transition metal cation exhibit unique behavior relative to those in sodium-exchanged zeolites, 37 judging from their 129 Xe NMR chemical shifts. However, our understanding of how extraframework cations influence the behavior of the Xe atom inside a zeolite is still lacking.…”

Section: Introductionmentioning

confidence: 99%

Site-specific Xe additions into Cu–ZSM-5 zeolite

Yumura

Yamashita

Torigoe

et al. 2010

Phys. Chem. Chem. Phys.

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Large-scale density functional theory (DFT) calculations found significant preferences of two-coordinated copper cations as Xe binding site in ZSM-5. Such site-preferences cannot be seen in usual adsorbents such as the CO or NO molecule inside Cu-ZSM-5 as well as the Xe atom inside alkali-metal exchanged ZSM-5s. A key factor in the specificity of the inner Xe atom is that interactions of the Xe atom with the extraframework copper cation are substantial relative to the extraframework alkali-metal cases, but weak relative to the CO and NO cases. Since the Xe atom can distinguish two-coordinated copper cations from others, it can be utilized to track sensitively the location of active sites of Cu-ZSM-5.

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Characterization of Cu+ ions in CuHZSM-5 zeolites and CuSAPO-34 molecular sieve Cu+ laser-induced luminescence and 129Xe-NMR diagnosis

Cited by 10 publications

References 33 publications

Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy

Determination of Zn Speciation, Siting, and Distribution in Ferrierite Using Luminescence and FTIR Spectroscopy

The removal of cesium ion with natural Itaya zeolite and the ion exchange characteristics

Site-specific Xe additions into Cu–ZSM-5 zeolite

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