The interactions between surface sulfate and surface vanadate species present on sulfated supported vanadia catalysts under dehydrated conditions have been investigated with infrared and Raman spectroscopies. The surface sulfate species present on sulfated TiO2, ZrO2, and Al2O3 supports and V2O5/TiO2, V2O5/ZrO2, and V2O5/Al2O3 catalysts have identical molecular structures, i.e., (M-O)3SdO, wher...

For the purposes of this study, hydroxyapatite (HA)-Al2O3-TiO2 nanobiomaterial with significant surface properties and biocompatibility capable of forming surface apatite was fabricated by cold-press and sintering method. Samples were examined for hardness and porosity. The results showed that in terms of hardness and porosity, sample A (50 wt% TiO2-30 wt% HA-20 wt% Al2O3) was superior to sampl...

abstract : alumina (al 2 o 3 ) is one of the most practical ceramics used in making ceramic-metal armours. to improve the properties of alumina, some other materials are added to it. in this paper, sic material as nano powder is added to alumina, and four armour samples of this new ceramic with different volume fractions (v.f. ) including 0%, 5%, 10% and 15% of sic particles are made. then, the...

H5PV2Mo10O40 polyoxometallate Keggin clusters supported on ZrO2, TiO2, SiO2, and Al2O3 are effective catalysts for CH3OH oxidation reactions to form HCHO, methyl formate (MF), and dimethoxymethane (DMM). Rates and selectivities and the structure of supported clusters depend on the surface properties of the oxide supports. Raman spectroscopy showed that Keggin structures remained essentially int...

Multifunctional nanocomposites Ag/Al2O3/TiO2@β-cyclodextrin-graphene oxide (AATG) incorporating graphene sheets, TiO2, and Ag/Al2O3 nanoparticles were prepared in two steps. We benefited from the inherent properties of β-cyclodextrin to create a stable aqueous solution capable self-assembling situ grown TiO2 on nanosheets. catalysts with high surface-to-volume ratio by combustion technique urea...

A numerical investigation has been carried out applying single phase approach on turbulent forced convection flow of water based Al2O3 and TiO2 nanofluids flowing through a horizontal circular pipe under uniform heat flux boundary condition applied to the wall. The effect of volume concentrations, Brownian motion and size diameter of nanoparticles on flow and heat transfer have been examined fo...

Aluminum(III)-modified TiO2 was prepared by sol-gel process via a sudden gelating method. The structure of the modified material and the local environment of aluminum were investigated using X-ray diffraction, HRTEM, XPS, 27Al MAS NMR, and xi-potential measurements. The effect of the aluminum modification on interaction between the dye and photocatalyst, the interfacial electron transfer proces...

In this study, hybrid AA1050/Al2O3/TiO2 composites have been produced via combined liquid casting and powder metallurgy techniques. Degassing was utilized to improve the wettability of molten aluminum alloys, then successful bonding generated between matrix reinforcement particles during technique. As base reinforcements, AA1050 alloy, Al2O3 TiO2 were taken, respectively. Then, content values 5...

this paper reports results of a study regarding the activities of nano structure mn/γ-al2o3 and γ-al2o3 catalysts for oxidation of 2-propanol (as a model of volatile organic compound). nanostructure of catalysts was revealed using xrd, sem and tem techniques. catalytic studies were carried out in u-shaped packed bed reactor under atmospheric pressure and at the reaction temperature of 150- 500°...

The entrance of Cd (II) to aqueous environments causes a major problem to human health. The current article examines the efficiency of TiO2 and γ-Al2O3 nanoparticles in Cd (II) removal from aqueous medium as influenced by different chemical factors, such as pH, initial concentration, background electrolyte, and ionic strength, in accordance with standard experimental methods. It conducts Batch ...