The Xerogel alumina catalyst was prepared by sol-gel
method in non-aqueous milieu, and the aerogel alumina
catalyst was prepared in the same method but it was dried at
by supercritical conditions. These catalysts were characterized
by XRD, BET, a
nd chemical adsorption methods. The
obtained results were compared to show the effect of
preparation process on the structural properties of the alumina.
Besides these results were compared with some oxides
supported on alumina, and the effect of distribution of these
oxides on the properties of alumina was investigated too.
Some samples of alumina supporting with sulfate ions and molybdenium were
prepared by impregnation method. Supported samples were calcinated at 550°C for 6h.
Presence of sulfate ions and molybdenium lead to decreasing of the specific surface area o
f
alumina, and in the ease of molybdenium the decreasing value was higher. The total pore
volume was decreased with the pore size was increased. XRD patterns showed that the
incorporation of sulfate ions and molybdenium did not affect crystalin structure of
alumina. FTIR spectra showed the bonding between sulfate ionsmolybdenium
and
alumina. The TG-DTA studies showed that the losses mass was decreased when the sulfate
ions and molybdenium were incorporated, sulfate ions and molybdenium oxide
decomposed at ~700°C and ~800°C respectively .
This study illustrates, and compares the results of the removal of phosphate
ions from aqueous solutions by using substances that have affinity to these ions,
i.e., these ions have relatively a high adsorbing tendency toward these
substances. Thre
e different adsorbing substances were used, they are alumina,
synthesized gatite, and hydrotalcite (abbreviation: HT). The results showed
that chemical equilibrium was achieved quickly in the case of HT. Regarding
the relative adsorbing ability of these three substances toward phosphate, and
its removal from aqueous solutions, it was found that both synthesized gatite,
and ignited HT at 500°C were both effective. The removal of phosphate ions
was maximum at pH=5. Ionic strength showed a positive effect on the
adsorption efficiency. The maximum adsorbing ability of these two adsorbing
materials was about 150 mg PO3
-4-P per gram of the adsorbing HT; whereas
the minimum efficiency was for aluminum oxide.
In this work composite hybrid materials were prepared from a base
material composed of epoxy and phenol - form aldehyde resins and
reinforced by 30% wt alumina and silica powders and asbestos
fibers. For samples were prepared with. Different ratio of
reinforcing material.
In this research a reaction of dehydration of methanol to
dimethyl ether on a microporous amorphous alumina xerogel
catalyst was studied. The catalyst possess a high surface area
(475 m2/g).
