Acid-Base Properties of Alumina Prepared from a Hydrated Product of Centrifugal Thermal Activation of Hydrargillite (CTA-Product)
Reaction Kinetics and Catalysis Letters
, E-ISSN: 1588-2837
||Acid-base properties, Alumina, CTA-product
Kul’ko Eugenia V.
Ivanova Aleksandra S.
Budneva Anna A.
Paukshtis Evgenii A.
Boreskov Institute of Catalysis, Novosibirsk 630090, Russia
Acid-base properties of aluminas prepared by thermal treatment of a hydrated CTA-product at 600°C were studied. The CTA-oxides, representing γ-Al2O3, were shown to contain terminal and bridged OH-groups. The concentration of the terminal OH-groups in the CTA-oxides was found to exceed their concentration in γ-Al2O3 prepared by dehydration of the “precipitated” pseudoboehmite, whereas the concentration of the bridged OH-groups in the CTA-oxides was lower than that in γ-Al2O3 prepared from pseudoboehmite. The total concentration of the surface Lewis acid sites in CTA-oxides varies within the limits of 2.80-4.14 mmol/m2 and is essentially above that in γ-Al2O3 (2.25 mmol/m2). The distinctive feature of the CTA-oxides is that their surface contains strong Lewis acid sites with νCO = 2220 and 2238 cm-1. The total concentration of basic sites in the CTA-oxides is lower than that in γ-Al2O3, however, in contrast to γ-Al2O3, they contain strong basic sites with νCDCl3 = 2200 cm-1.