Vibrational Spectroscopy of Zeolites

Abstract

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

Highly effective ammonia removal in a series of Brønsted acidic porous polymers: investigation of chemical and structural variations

“…, the proton fluctuates between carboxylic acid and ammonia. 33 Importantly, this observation sheds further light on the enhanced NH 3 adsorption capacity of P2-CO 2 H over P1-SO 3 H at low pressures, as discussed earlier. In spite of a weaker acidity, the high density of carboxylic acid groups in an interpenetrated structure creates strong binding sites for ammonia as well as a stabilizing polar environment for ammonium ions.…”

A multi-methodological study of the (K,Ca)-variety of the zeolite merlinoite

“…The powder mid-IR spectrum of merlinoite between 400-1300 cm −1 (Fig. 4) is very similar to that reported by Della Ventura et al (1993) and is dominated by the internal and external tetrahedral modes (Henderson and Taylor, 1977;Della Ventura et al, 1993;Zecchina et al, 2002). In particular, the experimental spectrum of Fig.…”

From gaseous HCN to nucleobases at the cosmic silicate dust surface: an experimental insight into the onset of prebiotic chemistry in space

“…The intensity of all the above manifestations is gradually reduced upon increasing the temperature from 150 K up to 300 K, while the signal of the free silanols is correspondingly restored. These results can be interpreted on the basis of the formation of weak SiOH⋯(HCN) hydrogen bonded complexes (see Zecchina et al 32 and references therein) fully reversible upon increasing the sample temperature from 150 K to 300 K with no evidence of the formation of other products. Indeed, the only manifestation observed in the spectrum at 300 K is the roto-vibrational contour of the HCN gas, i.e.…”