TY - JOUR
T1 - Acidic properties of [Al], [Ga] and [Fe] isomorphously substituted zeolites. Density functional model cluster study of the complexes with a probe CO molecule
AU - Strodel, Paul
AU - Neyman, Konstantin M.
AU - Knözinger, Helmut
AU - Rösch, Notker
N1 - Funding Information:
Financial support by the Bayerischer Forschungs-verbund Katalyse, by the Fonds der Chemischen Industrie, by the Deutsche Forschungsgemeinschaft via SFB 338, and by the Volkswagen-Stiftung (Project I/68 691) is gratefully acknowledged.
PY - 1995/7/7
Y1 - 1995/7/7
N2 - The Brønsted acid strength and related characteristics of bridging hydroxyl groups in [Al]-, [Ga]- and [Fe]-framework-substituted zeolites have been studied using a model cluster density functional approach based on a gradient-corrected exchange-correlation energy functional. The acidity is found to decrease in the order Al(OH)Si > Ga(OH)Si > Fe(OH)Si in agreement with existing experimental and theoretical results. The present quantification is based on the calculated deprotonation energy of H3Si(OH)TH3, on the adsorption energy of a CO probe molecule as well as on the changes of the vibrational frequencies and absolute IR intensities of the OH and of the CO modes induced by CO adsorption. The vibrational parameters of the carbonyl adsorption complex in [Fe]-zeolites are predicted.
AB - The Brønsted acid strength and related characteristics of bridging hydroxyl groups in [Al]-, [Ga]- and [Fe]-framework-substituted zeolites have been studied using a model cluster density functional approach based on a gradient-corrected exchange-correlation energy functional. The acidity is found to decrease in the order Al(OH)Si > Ga(OH)Si > Fe(OH)Si in agreement with existing experimental and theoretical results. The present quantification is based on the calculated deprotonation energy of H3Si(OH)TH3, on the adsorption energy of a CO probe molecule as well as on the changes of the vibrational frequencies and absolute IR intensities of the OH and of the CO modes induced by CO adsorption. The vibrational parameters of the carbonyl adsorption complex in [Fe]-zeolites are predicted.
UR - http://www.scopus.com/inward/record.url?scp=0001489486&partnerID=8YFLogxK
U2 - 10.1016/0009-2614(95)00583-P
DO - 10.1016/0009-2614(95)00583-P
M3 - Article
AN - SCOPUS:0001489486
SN - 0009-2614
VL - 240
SP - 547
EP - 552
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 5-6
ER -