Estudio espectroscópico y termodinámico de la adsorción de CO y CO2 en zeolitas
- Fiol Bibiloni, Gabriel
- Montserrat Rodríguez Delgado Director
- Carlos Otero Areán Director
Defence university: Universitat de les Illes Balears
Fecha de defensa: 07 June 2013
- María Carmen Rosselló Matas Chair
- Gemma Turnes Palomino Secretary
- José Bernardo Parra Soto Committee member
- Sofía Calero Committee member
- Camino Trobajo Fernández Committee member
Type: Thesis
Abstract
The adsorption complexes of CO in the zeolites Na-ZSM-5 and K-ZSM-5 were investigated by means of variable-temperature IR spectroscopy and DFT calculations on periodic models. The following types of species were found, M+ CO, M+ OC y M+ CO M+ (M = Na, K), which were characterized by their corresponding C¿O stretching frequency and standard adsorption enthalpy. Also, the adsorption complexes of CO2 in the zeolites K-FER and K-L were studied. K-FER gave the species OCO y K+ OCO K++; K-L gave only the K+ OCO adsorption species. Finally, the effect of progressive substitution of Na+ or K+ for H+ in the zeolites H-ZSM-5 and H-Y was investigated; showing that such a substitution constitutes and effective means to tailor the zeolite Brønsted acid strength, which decreases when the degree of substitution of the alkali metal cation for the proton increases.