Surface chemistry of Rh carbonyls and nitrosyls on dealuminated Y-zeolite at low temperature

Mießner, H.; Burkhardt, I.; Gutschick, D.; Zecchina, Adriano; Morterra, C.; Spoto, Giuseppe

doi:10.1039/ft9908602321

Cited by 44 publications

(68 citation statements)

References 21 publications

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“…Similarly, on Rh C -Y zeolite a complete set of Rh C (CO) n (n D 1,2,3,4) complexes can be formed in steps upon increasing the equilibrium pressure of CO. 107 Nitrogen, NO and CO/NO mixed complexes can be formed as well in the cavities 108 so showing that the Rh C intrazeolite chemistry is very rich and diversified.…”

Section: The Vibrational Spectra Of Molecules Adsorbed On Charge Balamentioning

confidence: 98%

Vibrational Spectroscopy of Zeolites

Zecchina¹,

Spoto²,

Bordiga³

2001

Handbook of Vibrational Spectroscopy

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The sections in this article are The Structure of Zeolites and Zeotype Materials The Vibrational Spectra of Zeolites and of Zeolitic Materials: General Considerations Framework Modes IR Modes Associated with the B rØnsted Groups and their Modifications upon Interaction with Adsorbates The Spectrum of Free B rønsted Groups Modifications Induced by Adsorbates The Vibrational Spectra of Molecules Adsorbed on Charge Balancing Cations Cation and Cation‐Sensitive Modes: Perturbations Induced by Adsorption Vibrational Spectra of Molecules Adsorbed on Strong Lewis Centers Vibrational Spectroscopies in Reaction Dynamics Studies on Zeolites

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Section: The Vibrational Spectra Of Molecules Adsorbed On Charge Balamentioning

confidence: 98%

Vibrational Spectroscopy of Zeolites

Zecchina¹,

Spoto²,

Bordiga³

2001

Handbook of Vibrational Spectroscopy

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“…It has been assumed that at lower temperature they may form trinitrosyls or fournitrosyls [219,239]. It has been assumed that at lower temperature they may form trinitrosyls or fournitrosyls [219,239].…”

Section: Rh ϩ Nitrosylsmentioning

confidence: 99%

Identification of Neutral and Charged N_xO_ySurface Species by IR Spectroscopy

2000

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“…It is difficult to give definite conclusions on the stability of the Cu + (H 2 O) complexes, but is seems (see below) they are slightly more stable than the Cu + -NO species. Based on the stability, we studied the adsorption of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 14…”

Section: Adsorption Of 15 Nmentioning

confidence: 99%

“…Thus, while only dicarbonyls are formed with oxide-supported rhodium, Rh + (CO) 3 and Rh + (CO) 4 species are produced with Rh + sites in zeolites. 14,15 Copper-exchanged zeolites are subjected to a continued interest. They are effective catalysts in many reactions, e.g.…”

mentioning

confidence: 99%

Surprising Coordination Chemistry of Cu⁺Cations in Zeolites: FTIR Study of Adsorption and Coadsorption of CO, NO, N₂, and H₂O on Cu–ZSM-5

et al. 2015

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Cations exchanged in zeolites are generally characterized by a low coordination number and can thus attach simultaneously more than one small guest molecule. For instance, Cu + ions in ZSM-5 can accept, at low temperature, up to three CO and up to two NO molecules. However, only one N 2 molecule can be coordinated to such sites. Although mixed aqua-carbonyl and aqua-dinitrogen complexes are formed, no mixed carbonyl-nitrosyl, carbonyl-dinitrogen or nitrosyl-dinitrogen species can be produced. Thus, adsorption of NO on CO precovered sample results in segregation of the CO adsorption layer according to the reaction: 2 Cu + -CO + 2 NO → Cu + (CO) 2 + Cu + (NO) 2 . Adsorption of N 2 on NO precovered sample leads to a similar process: 2 dinitrogen complexes are produced during CO -N 2 coadsorption. The role of the ligand and the nature of the bond on the formation of geminal and mixed-ligand complexes are discussed. the change of the ligand does not affect the process and consequently mixed ligand species, e.g. Na + (CO)(N 2 ) in NaY, have been isolated. 2 For catalysis, the formation of geminal ad-species with transition metal cations in zeolites is more important. However, in these cases the situation could be complicated. 11 First of all, the socalled "complex-specified" geminal species can be produced with particular cation-adsorbate systems. For instance, with Rh + cations CO forms Rh + (CO) 2 dicarbonyls irrespective of the support. These species do not produce monocarbonyls upon decomposition. 14,15,39 In this case the driving force of the formation of the complexes is the achievement of a stable electron configuration. However, even in these cases the cation coordination is important. Thus, while only dicarbonyls are formed with oxide-supported rhodium, Rh + (CO) 3 and Rh + (CO) 4 species are produced with Rh + sites in zeolites. 14,15 Copper-exchanged zeolites are subjected to a continued interest. They are effective catalysts in many reactions, e.g. selective catalytic reduction of NO x with hydrocarbons, 40,41 decomposition of NO 42 and N 2 O, 43 oxidation of methane to methanol, 44 oxidative carbonylation of methanol to dimethyl carbonate, 45 etc. That is why the coordination state of copper in zeolites has attracted the interest of many researchers. In what follows we shall concentrate on Cu + sites because they demonstrate fascinating coordination chemistry.In 1994 Zechina et al. 18 reported that CO adsorption at room temperature on Cu I -ZSM-5 resulted in formation of Cu + (CO) 2 dicarbonyl species characterized by two IR bands: ν s at 2178 and ν as at 2151 cm -1 . Decrease of the CO equilibrium pressure led to loss of one of the CO ligands and conversion of these species into monocarbonyls (2157 cm -1 ). In contrast, at low temperature a large part of dicarbonyls were converted into tricarbonyls (2190, 2164 and 2140 cm -1 ). Later on, the results were confirmed by other authors 21,22,26 and similar situation was also . EXPERIMENTAL The starting zeolite material was prepared by calcination of NH 4 ZSM-5...

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Surface chemistry of Rh carbonyls and nitrosyls on dealuminated Y-zeolite at low temperature

Cited by 44 publications

References 21 publications

Vibrational Spectroscopy of Zeolites

Vibrational Spectroscopy of Zeolites

Identification of Neutral and Charged N_xO_ySurface Species by IR Spectroscopy

Surprising Coordination Chemistry of Cu⁺Cations in Zeolites: FTIR Study of Adsorption and Coadsorption of CO, NO, N₂, and H₂O on Cu–ZSM-5

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Surface chemistry of Rh carbonyls and nitrosyls on dealuminated Y-zeolite at low temperature

Cited by 44 publications

References 21 publications

Vibrational Spectroscopy of Zeolites

Vibrational Spectroscopy of Zeolites

Identification of Neutral and Charged NxOySurface Species by IR Spectroscopy

Surprising Coordination Chemistry of Cu+Cations in Zeolites: FTIR Study of Adsorption and Coadsorption of CO, NO, N2, and H2O on Cu–ZSM-5

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Identification of Neutral and Charged N_xO_ySurface Species by IR Spectroscopy

Surprising Coordination Chemistry of Cu⁺Cations in Zeolites: FTIR Study of Adsorption and Coadsorption of CO, NO, N₂, and H₂O on Cu–ZSM-5