Forces between fully hydroxalated silica surfaces were measured using an atomic force microscope. The measurements were conducted in Nanopure water and in solutions containing various organic solutes such as methanol, ethanol, trifluoroethanol (TFE), and pyridine. The results obtained in Nanopure water showed a strong short-range repulsive force at distances below 15 nm. This non-DLVO force can...

Partially purified thromboxane synthase from human platelets converted prostaglandin Gz to two products. These were transformed to 12-hydroxy-5,8,10heptadecatrienoic acid and thromboxane B2 by stannous chloride reduction and to 12-keto-5,8,10-heptadecatrienoic acid and 15-ketothromboxane Bz by lead tetraacetate dehydration. Trapping with methanol after short incubations of substrate with enzy...

H-ZSM-5 nano-zeolites were synthesized by hydrothermal method using tetrapropylammonium hydroxide (TPAOH) as a template in the presence of various TPABr concentrations. The effect of different TPABr/TPAOH molar ratios was studied on the catalytic performance of dehydration of methanol to dimethyl ether (DME) in a fixed bed reactor under the same operating conditions (T=300°C, P=1 atm, and WHSV=...

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated methanol present in crude provide situ via its steam reforming reaction. This paper focuses on the promoting effect of Pd reactivity a Cu/Zn/Al2O3 catalyst. Adding 2 wt% onto Cu/ZnO/Al2O3 catalyst significantly improved selectivity from 63.0% 82.4% and conversion 70.2% 99.4%. enhan...

An extensive series of supported WO3/ZrOx (OH)4−2x catalysts (WZrOH) were synthesized by standard aqueous impregnation of ammonium metatungstate into an amorphous ZrOx (OH)4−2x metastable support, followed by high-temperature calcination (at 773–1173 K). The supported WZrOH catalysts were also compared with well-defined model supported WO3/ZrO2 catalysts (WZrO2) consisting of a thermally stable...

The flexibility of eight aluminium hydroxo terephthalates [Al(OH)(BDC-X)]·n(guest) (BDC = 1,4-benzene-dicarboxylate; X = -H, -CH3, -Cl, -Br, -NH2, -NO2, -(OH)2, -CO2H) crystallising in the MIL-53-type structure was investigated upon thermal dehydration of as-made samples, superhydration and methanol adsorption/desorption using in situ powder X-ray diffraction (PXRD). Profile fitting was used to...

The production processes included catalytic dehydration of methanol in an adiabatic fixed-bed reactor and two columns product separations. In this study, the technological process for dimethyl ether (DME) synthesis is built on PRO/II platform based on the combined parameters of the reaction dynamic model for methanol dehydration reaction, the improved NRTL model of the liquid phase, the PR mode...

This paper investigates hollow and porous alumina nanospheres that were previously synthesized to be used for the dehydration of methanol to dimethyl ether (DME). As hollow nanostructures possess characteristics such as low density and high surface to volume ratio, their catalytic activity between hollow and porous structure is compared. For this purpose, three most important parameters (acidit...