Influence of Peptization and Ethanol Washing on the Pore‐Structure Evolution of Sol‐Gel‐Derived Alumina Catalyst Supports

Abstract

Alkoxide-derived boehmite precipitates were subjected to different post-precipitation treatments to obtain a peptized sol, an unpeptized slurry, and an ethanol-washed gel precipitate. These materials were dried further to obtain the corresponding gels. Changes in the surface area, porosity, and pore size with temperature and the phase-transformation behavior from ␥-alumina to ␣-alumina were studied using X-ray diffractometry, differential scanning calorimetry, and physical adsorption/desorption measurements. Gels that were obtained from the peptized sol retained the lowest porosity, in comparison to the ethanol-washed gel and the gel that was prepared from the aqueous slurry.

Hierarchically Porous Ceramics from Diatomite Powders by Pulsed Current Processing

“…M acroporous ceramics provide the possibility to combine high permeability with good mechanical, thermal, and chemical stability which is attractive for a wide range of industrial applications 1–3 . Liquid metal filters of alumina, 4 diesel soot filters of alumina and zirconia 5 , and catalyst supports of alumina and corderite 6–8 are examples where porous ceramics are already commercially established, while other applications including e.g. hard tissue and bone scaffolds are still in development 9–11 .…”

Hydrothermal Synthesis of Nanosized Titania Powders: Influence of Tetraalkyl Ammonium Hydroxides on Particle Characteristics

“…Peptization of the amorphous TiO 2 also greatly affects the packing behavior of TiO 2 powder. Kumar and co-workers 4,5 and Nair et al 9 compared the packing behavior of unpeptized and peptized samples and concluded that the lessagglomerated samples that were obtained from the peptized species created an efficient packing of particles, whereas the unpeptized species favored the formation of structures with greater porosity and larger pore sizes.…”

Facile Synthesis of α-MnO2 with a 3D Staghorn Coral-like Micro-Structure Assembled by Nano-Rods and Its Application in Electrochemical Supercapacitors

“…A further process is required to form the MnO2 structures. It was proved that, if the material is processed in an alcohol-based environment, a fine growth unit for formation of metal oxide is likely to form [33,34]. To avoid a process at high temperatures that can result in a For material characterization, X-ray diffraction (XRD) (Bruker D-8 diffractometer, Madison, WI, USA) was used for the determination of crystal structure of synthesized products.…”

“…A further process is required to form the MnO 2 structures. It was proved that, if the material is processed in an alcohol-based environment, a fine growth unit for formation of metal oxide is likely to form [33,34].…”