Alumina, thanks to its superior thermal and dielectric properties, has been the leading substrate over several decades, for power and microelectronics circuits. However, alumina lacks thermal stability since its temperature coefficient of resonant frequency (τf) is far from zero (-60 ppmK-1). The present paper explores the potentiality of a ceramic composite 0.83ZnAl2O4-0.17TiO2 (in moles, abbr...

Copper oxide supported on γ-alumina nanoparticles were prepared and were well characterized. In this study catalytic activities of the supported copper oxide for oxidation of cyclohexene to 2-cyclohexene-1-ol, 2-cyclohexene-1-one and cyclohexene oxide with TBHP and H2O2 as the oxidant, in the liquid phase were considered. For the CuO/γalumina nanocomposites, acetonitrile as the solvent was empl...

The surface species formed by the reaction of gas-phase dimethylzinc with self-supported alumina pellets are examined by Fourier transform infrared spectroscopy. Dimethylzinc reacts with the surface -OH groups of alumina at room temperature evolving methane and yielding mainly surface Al-O-Zn-CH3 species. A small amount of CH3 species appears to bind to the Lewis acid sites of alumina as well, ...

Significant progress has been made on the synthesis and application of mesoporous γ-alumina. To date, little attention has been paid to the synthesis of microporous crystalline alumina. Here, fabrication of microporous crystalline γ-alumina using a microporous covalent triazine framework (CTF-1) as a template is described. Microporous crystalline γ-alumina with a micro-meso binary pore system w...

In the smelting of aluminium, HF fumes are produced that are subsequently trapped by absorption onto alumina. The factors that affect the adsorption capacity of alumina have been studied previously and are weU established, but the mechanism by which HF adsorbs onto the alumina surface is not well understood. In this study, x-ray photoelectron spectroscopy (XPS) was used to investigate the natur...

The interaction of rhenium oxide with an alumina support is examined over a wide range of conditions (rhenium oxide loading, calcination temperature and environment) using laser Raman spectroscopy (LRS) and X-ray absorption near-edge spectroscopy (XANES). These structural probes reveal that supported rhenium oxide on alumina is present as an atomically dispersed surface [ Re04] ads species coor...

Alumina-supported vanadium particles were prepared under ultrahigh vacuum (UHV) conditions and characterized with respect to their structural and CO adsorption properties. As supporting oxide, we used a thin, well-ordered alumina film grown on NiAl(110). This allows the application of scanning tunneling microscopy (STM), infrared reflection-absorption spectroscopy (IRAS), and X-ray photoelectro...

A strong solid/liquid interfacial interaction is found between porous alumina and graphene oxide (GO) aqueous dispersion, which promotes a fast enrichment of GO on the alumina surface and results in the formation of a GO hydrogel.

Polycyclic aromatic hydrocarbons (PAHs) are known to be present in many astrophysical objects and environments, but our understanding of their formation mechanism(s) is far from satisfactory. In this paper, we describe an investigation of the catalytic conversion reaction of acetylene gas to PAHs over pyroxene and alumina. Crystalline silicates such as pyroxenes (with general formula [Mg, Fe]Si...

The silver toughened alumina ceramics, which were fabricated via a conventional ceramic processing route using commercially available alumina and silver oxide powders as the starting materials, exhibit a higher fracture toughness (6 to 9 MPamo.5) than the monolithic alumina ceramic ( 2.5 to 3.0 MPamo.5). The weak interfacial bonding between the silver inclusions and the alumina matrix is charac...