TY - JOUR
T1 - Highly Dispersed SiOx/Al2O3 Catalysts Illuminate the Reactivity of Isolated Silanol Sites
AU - Mouat, Aidan R.
AU - George, Cassandra
AU - Kobayashi, Takeshi
AU - Pruski, Marek
AU - Van Duyne, Richard P.
AU - Marks, Tobin J.
AU - Stair, Peter C.
N1 - Publisher Copyright:
© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2015/11/1
Y1 - 2015/11/1
N2 - The reaction of γ-alumina with tetraethylorthosilicate (TEOS) vapor at low temperatures selectively yields monomeric SiOx species on the alumina surface. These isolated (-AlO)3Si(OH) sites are characterized by PXRD, XPS, DRIFTS of adsorbed NH3, CO, and pyridine, and 29Si and 27Al DNP-enhanced solid-state NMR spectroscopy. The formation of isolated sites suggests that TEOS reacts preferentially at strong Lewis acid sites on the γ-Al2O3 surface, functionalizing the surface with "mild" Brønsted acid sites. For liquid-phase catalytic cyclohexanol dehydration, these SiOx sites exhibit up to 3.5-fold higher specific activity than the parent alumina with identical selectivity.
AB - The reaction of γ-alumina with tetraethylorthosilicate (TEOS) vapor at low temperatures selectively yields monomeric SiOx species on the alumina surface. These isolated (-AlO)3Si(OH) sites are characterized by PXRD, XPS, DRIFTS of adsorbed NH3, CO, and pyridine, and 29Si and 27Al DNP-enhanced solid-state NMR spectroscopy. The formation of isolated sites suggests that TEOS reacts preferentially at strong Lewis acid sites on the γ-Al2O3 surface, functionalizing the surface with "mild" Brønsted acid sites. For liquid-phase catalytic cyclohexanol dehydration, these SiOx sites exhibit up to 3.5-fold higher specific activity than the parent alumina with identical selectivity.
KW - alcohol dehydration
KW - atomic layer deposition
KW - heterogeneous catalysis
KW - silica-alumina
KW - solid acid
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U2 - 10.1002/anie.201505452
DO - 10.1002/anie.201505452
M3 - Article
AN - SCOPUS:84945434809
VL - 54
SP - 13346
EP - 13351
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
SN - 1433-7851
IS - 45
ER -