A "sandwich" type polyoxometalate catalyst ([MeN(n-C8H17)3]12[WZn3(ZnW9O34)2]) was very efficiently recycled by nanofiltration with almost quantitative retention, using an alpha-alumina supported mesoporous gamma-alumina membrane.

The phase transformation of aluminum hydrates yields various forms of alumina (d, q, K) and eventually alpha-alumina. The decrease in the specific surface area of alumina upon heat treatment is due to changes in crystalline structure and hence a decrease in the porosity of the material, Although the conversion of gamma-alumina to alpha-structure takes place with a lowering in surface area and p...

Analysis of DRIFTS spectra was used for a quantitative study of competitive adsorption of myristic and salicylic acids onto kaolinite or gamma-alumina. Peaks unique to the ring or the chain were selected and single molecule studies used as calibration. Samples were exposed to hexane solution containing equal molecular quantities of each acid. The surface loading of salicylic acid was not influe...

The study reported herein indicated the stabilization mechanisms at work when copper-laden sludge is thermally treated with gamma-alumina and kaolinite precursors, and evaluated the prolonged leachability of their product phases. Four copper-containing phases - copper oxide (CuO), cuprous oxide (Cu(2)O), copper aluminate spinel (CuAl(2)O(4)), and cuprous aluminate delafossite (CuAlO(2)) - were ...

ammonium carbonate and ammonium sulfate have been proposed and used as two new fuels for synthesizing gamma alumina nanoparticles. the prepared samples have been characterized by x-ray diffraction (xrd), 2 n  adsorption (bet) and transmission electron microscopy (tem). a comparison has been made between the properties of the nanoparticles synthesized by these two fuels and other conventional fu...

the series of mono-metallic and bi-metallic catalysts have been prepared by impregnatingwith solutions containing compound of h2ptc15,nbc15 and lml hc1 (0.1 mol). the activityand selectivity of the catalysts have been determined under conditions at 450-500°c, 15-30atm. molar ratio h2/c7h16=5 and vvh=1.5/h for converting n-heptane. under theseexperimental conditions it has been established that ...

In the present study, the gamma alumina (γ-Al2O3) nano powders have been prepared with addition of 1%mol Co using an aqueous sol-gel method at lower temperature than the pure gamma alumina. The synthesis process accomplished by partial hydrolysis of the aqueous solution of metallic ions Al3+ and Co2+, with ammonia. The Al(NO3)3.9H2O and Co(NO3)2.6H2O salts were used as cations sources. The obta...

A particular type of mesopore extrudates gamma alumina was prepared; which is used as the catalyst in the heavy oil desulfurization unit. Extrudates gamma-alumina support has been made of the boehmite powder from Nephlinsinite mine ores (Surface Area (S.A.) >200 m2/g, Pore Volume (P.V.) =0.48 cm3/g, Average Pore Diameter (A.P.D.) = 8.10 nm); then, many samples of extru...

group viii b metal oxides supported on gamma-alumina were investigated as catalysts and promoters of moo3 hydrodesulfurization catalysis. superior promotion was observed in pbo promoted catalyst compared to that of coo, the typically accepted promoter. other metal oxides, sno and ho2o3 exhibited reasonable hydrodesulfurization catalysis promotion but lower than for coo promoted catalyst.