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El-Shobaky, G.A.; Doheim, M. M.; Turky, A.M.; El-Boohy, H. A.

doi:10.1023/a:1023360328078

Cited by 4 publications

(4 citation statements)

References 22 publications

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“…The total loss in weight by heating in air up to 1000°C was 17.67% and the loss in weight accompanying the different stages was 4.72, 8.2, 3.65 and 1 .l% respectively. The first stage, at 65.8"C, corresponds to desorption of physisorbed water, the second stage at 228"C, indicates the thermal decomposition of ammonium meta vanadate (7) according to :…”

Section: Resultsmentioning

confidence: 99%

“…It has been reported that heating of NH4V03 in an inert atmosphere or under a reduced pressure of Torr led to the formation of V307 (2,4,6) while in air it decomposed giving V205via an intermediate compound (NH4)2V6016 (4,5). The thermal decomposition, in air of ammonium metavanadate supported on A1203 made the object of our previous investigation (7). The presence of aluminium oxide did not modify the mechanism of thermal decomposition of NH4V03.…”

Section: Introductionmentioning

confidence: 94%

“…The effect of doping with certain foreign oxide as Li20, to our knowledge, has not yet been studied. It is known that Liz0 could be dissolved in transition metal oxides forming solid solutions (8)(9)(10)(11)(12)(13)(14)(15)(16)(17). This process is normally followed by significant modifications in physicochemical, thermal, electrical, surface and catalytic properties of doped oxides (8- 1 7).…”

Section: Introductionmentioning

confidence: 99%

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SOLID‐SOLID INTERACTIONS IN PURE AND Li₂O‐DOPED V₂O₅/AI₂O₃ SYSTEM

Abdalla

El-Shobaky

Hassan

1994

Bulletin des Soc Chimique

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The effects of calcination temperature (500-1000°C) and lithium oxide-doping (4 and 10 mole %) on solid-solid interactions between A1203 and V205 were investigated using DTA, TG and their derivatives together with XRD techniques.The results obtained revealed that no solid-solid interaction between vanadium and aluminium oxides occured at 500°C. These oxides interacted in part, at 650°C to produce AIV04, the completion of this reaction requires a prolonged heating at this temperature. LinO-doping much enhanced the interaction yielding AIV04, the presence of 4 mole %was found sufficient to stimulate the complete conversion of V205 into aluminium vanadate. Aluminium vanadate produced in the case of pure mixed solids decomposed entirely by heating at 750°C giving a well crystallized VnOsand an amorphous alumina. On the other hand, lithium oxide-doping much increased the thermal stability of A N 0 4 at 750°C and led also to the formation of AIV03 and LiV10025 phases.The heating of pure mixed oxides in air at 1000°C resulted in the formation of alpha-alumina (corrundum) together with V2O5. This treatment, in the case of doped mixed solids, effected the formation of alpha-AlnO3, V2O5 and LiVlo025 phases. The last compound was formed at 750°C and remained stable by heating at 1000°C. The promotion effect of Li2O in AIV04 formation was tentatively attributed to dissolution of a small portion of Li2O in V205 lattice with subsequent increase in the mobility of V+5 ions.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

SOLID‐SOLID INTERACTIONS IN PURE AND Li₂O‐DOPED V₂O₅/AI₂O₃ SYSTEM

Abdalla

El-Shobaky

Hassan

1994

Bulletin des Soc Chimique

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“…It is well known that the EDX technique supplies an accurate determination of relative atomic concentration of different elements present on their outermost surface layers. [34][35][36][37][38][39][40] The bulk concentration of solids investigated was readily determined on the basis of nominal composition of these solids. Surface and bulk compositions of various solids are given in Table 3.…”

Section: Surface Characteristics Of Various Prepared Solidsmentioning

confidence: 99%

Structural, surface and catalytic properties of pure and ZrO₂‐doped nanosized cobalt‐manganese mixed oxides

Ibrahim

Badawy²,

El-Shobaky

et al. 2013

Can J Chem Eng

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The role of ZrO2‐doping of CoO–Mn2O3 system on its structural, surface and catalytic properties was studied using XRD, EDX, nitrogen adsorption at −196°C and H2O2‐decomposition at 30–50°C. The results revealed that all solids calcined at 300–500°C consisted of nanosized Co2MnO4 as a major phase together with Co3O4 phase. The surface and bulk compositions of pure and variously doped solids were completely different from each other's. The concentration of surface manganese species was much higher than that of cobalt. The addition of the smallest amount of ZrO2 (0.75 mol%) much increased the surface concentration of manganese species. The increase of calcination temperature of all solids increased progressively the catalytic activity which increased by doping with the smallest amount of ZrO2 then decreased by doping with further amounts of ZrO2 dopant falling to values smaller than that measured for pure sample.

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