The reaction of formaldehyde with β-diketones (Hantzsch reaction) has been often employed for derivatizing formaldehyde to the fluorescent compounds.1,2 Among βdiketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone, Fig. 1) seems to be the most promising because of the strong fluorescence intensity and stability of the formed compound. Recently, we developed a method for concentrating trace hyd...

In this work, the desorption of furfural, which is a competitive intermediate during the production of biofuel and valuable aromatic compounds, was studied using pure alumina, as well as alumina impregnated with iron and platinum oxides both individually and in combination, using thermogravimetric analysis (TGA). The bimetallic sample exhibited the lowest desorption percentage for furfural. Hig...

Supported sulfated zirconia catalysts with zirconia contents of 10, 20 and 50 wt% were prepared by impregnation of SiO2 and γ-Al2O3 supports with H2SO4/Zr(SO4)2 solutions followed by calcination at 923 K. The catalysts were characterized by X-ray diffraction, extended X-ray absorption fine structure measurements, thermal analysis, UV–vis spectroscopy, and electron microscopy. Tetragonal zirconi...

In the present study, the effect of alumina on the pore structure and hydrothermal stability of nanostructured silica was investigated. SiO2 and SiO2-15wt%Al2O3 membranes were prepared by dip coating on mesoporous γ-Al2O3 coated macroporous α-alumina support. The particle sizes of sol were increased by adding of alumina to silica...

Consequences of loading level of ceria (5, 10 and 20-wt%) on the structural, textural and surface acid-base properties as well as the impacts on catalytic activity towards isopropanol decomposition on pure and phosphated alumina is described. The obtained results indicated that composites mainly kept γ-alumina structure and the addition of ceria and/or phosphate has no effect on the bulk struct...

The production of dimethyl ether (DME) as compared to methanol from synthesis gas allows for increased conversions in a single pass. A challenge this process is the combination and dehydration functionalities catalyst without mutual negative interference their performances. Here, we studied use hydrated niobium pentoxide (Nb2O5·nH2O) phosphate (NbOPO4) with copper-based direct DME, while gamma-...

Solidification of cryolite (Na3AlF6)-based bath takes place at different rates along the sideledge, and around alumina rafts and new anodes. The solidification rate has a significant impact on the structure and the chemical composition that determine the thermal conductivity and thus the thickness of sideledge, or the duration of the existence of the temporary frozen bath layers in other cases....

alumina is one of the most widely used ceramic materials as catalysts, catalyst supports and absorbents, and also wear resistant coating. this study focused on fabricating and characterizing of alumina ceramic nanoparticles fabricated using new and simple sol-gel method. aluminium oxide (al2o3) nanoparticles were synthesized by iron (iii) nitrate 9-hydrate as precursor. physicochemical properti...

Dehydration of glycerol was performed over heteropoly acids (HPA), viz., silicotungstic acid (H-SiW), phosphotungstic acid (H-PW), and phosphomolybdic acid (H-PMo), supported high surface area γ-alumina (HSAI-S25) catalysts. Various physico-chemical studies of these supported catalysts indicate high dispersion of the active (HPA) species on the support surface. It was observed that the catalyst...

A novel green controlled synthesis method is proposed in this paper. Mesoporous alumina was prepared by using sodium aluminate extracted from red mud as an aluminum source. The influence mechanism of temperature, template agent and concentration on MA properties studied systematically. results show that the mesoporous γ-alumina has a good catalytic activity short-range arrangement, medium acidi...