Synthesis of nano-sized porous γ-alumina powder via a precipitation/digestion route

Potdar, H.S.; Jun, Ki‐Won; Bae, Jong Wook; Kim, Seung-Moon; Lee, Yun-Jo

doi:10.1016/j.apcata.2007.01.055

Cited by 136 publications

(98 citation statements)

References 22 publications

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“…Here again the difference in weight loss 9.3 % can be also attributed to the desorption of physisorbed water [39] as well as dehydroxylation occurring when gibbsite transformed into η-Al 2 O 3 [31]. For AN550 catalyst, the weight loss is 7.3% which can be attributed to the desorption of physisorbed water [39], as there is no weight loss due to the complete transformation to η-Al 2 O 3 . From Figure (3)a, the most suitable temperature to prepare η-Al 2 O 3 is 550°C and is in good agreement with the XRD data.…”

Section: Tgamentioning

confidence: 87%

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Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

Osman

Abu‐Dahrieh

Rooney

et al. 2012

Applied Catalysis B: Environmental

124

100

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Highlights Effect of precursors on the catalytic performance of alumina. AN samples is higher activity than AC, while AN550 is the optimum one. The AN550 showed methanol conversion and DME selectivity of 72% and 100% at 250 °C, respectively. Acid site density affected catalytic performance among the catalysts with alumina phase. Synthesis of alumina catalyst with high activity compared to commercial γ-Al 2 O 3 .Page 3 of 33 A c c e p t e d M a n u s c r i p t Abstract Dimethyl ether (DME) is amongst one of the most promising alternative, renewable and clean fuels being considered as a future energy carrier. In this study, the comparative catalytic performance of γ-Al 2 O 3 prepared from two common precursors (aluminium nitrate (AN) and aluminium chloride (AC)) is presented. The impact of calcination temperature was evaluated in order to optimise both the precursor and pre-treatment conditions for the production of DME from methanol in a fixed bed reactor. The catalysts were characterized by TGA, XRD, BET and TPD-pyridine. Under reaction conditions where the temperature ranged from 180-300˚C with a WHSV= 12.1 h -1 it was found that all the catalysts prepared from AN(η-Al 2 O 3 ) showed higher activity, at all calcination temperatures, than those prepared from AC(γ-Al 2 O 3 ). In this study the optimum catalyst was produced from AN and calcined at 550 ˚C.This catalyst showed a high degree of stability and had double the activity of the commercial γ-Al 2 O 3 or 87% of the activity of commercial ZSM-5 (80) at 250 ˚C.

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Section: Tgamentioning

confidence: 87%

“…Theoretically, the transformation of Gibbsite Al(OH) 3 to η-Al 2 O 3 should be associated with 34.6% weight loss. The difference in weight loss of 7.68 % can be attributed to the desorption of physisorbed water [39]. For the AN300 catalyst, the percentage weight loss was 24.5%.…”

Section: Tgamentioning

confidence: 95%

Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

Osman

Abu‐Dahrieh

Rooney

et al. 2012

Applied Catalysis B: Environmental

124

100

View full text Add to dashboard Cite

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“…The nano-γ-Al 2 O 3 was prepared by sol-gel method according to a procedure described [40]. In a typical experiment, aluminum nitrate (15.614 g) was added to 400 mL of deionized water.…”

Section: Synthesis Of Nano-γ-al 2 O 3 Catalystmentioning

confidence: 99%

“…In the recent years, the use of nano-structured ZnO [38], nano-sulfated zirconia [39], nano-γ-alumina [40], and nano-ZSM-5 zeolite [41], catalysts has received considerable interest in organic synthesis. This extensive application of heterogeneous catalysts in synthetic organic chemistry can make the synthetic process more efficient from both environmental and economic point of view [42] and used-catalyst can be easily recycled.…”

Section: Introductionmentioning

confidence: 99%

A simple and efficient approach for synthesis of 1,4-dihydro-pyridines using nano-crystalline solid acid catalyst

Teimouri

Ghorbanian²,

Moatari³

2013

Bull. Chem. Soc. Eth.

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ABSTRACT. A simple highly versatile and efficient synthesis of various 1,4-dihydropyridines in the condensation of aromatic aldehydes with β-dicarbonyl compounds and ammonium acetate in the presence of nano-sulfated zirconia, nano-structured ZnO, nano-γ-alumina and nano-ZSM-5 zeolites, as catalyst in the ethanol at moderate temperature is presented. The advantages of method are short reaction times and milder conditions and easy work-up. The catalysts can be recovered for the subsequent reactions and reused without any appreciable loss of efficiency.

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“…For these reasons, it is widely employed in the chemical and petrochemical industries. [15][16][17][18][19][20][21][22] In this paper, we report the preparation of the P2W15@Al2O3 composite material by immobilization of POMs onto spherical γ-Al2O3 particles (Scheme 1) and we discuss its catalytic efficacy for the oxygenation of thioethers.…”

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confidence: 99%

Covalent Immobilization of Polyoxotungstate on Alumina and Its Catalytic Generation of Sulfoxides

Hong

Win

Zhang

et al. 2016

Chemistry A European J

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Structural and chemical stability of the immobilized polyoxometalates (POMs)-containing catalysts is one crucial factor for their industrial application. In this work, we discuss the preparation of a novel P2W15@Al2O3 catalyst using a facile condensation reaction between the tri-lacunary POM of Na12[α-P2W15O56]·24H2O (P2W15) and the hydroxyl groups on the surface of the spherical γ-Al2O3 under acidic conditions. The heterogeneous catalyst was characterized by the 31 P NMR, FT-IR, XRD, XPS, TG, Raman, HR-TEM and BET. The P2W15@Al2O3 catalyst showed excellent stability, highly efficient reactivity and selectivity for the oxygenation of thioethers to sulfoxides which are a very useful intermediate in organic synthesis and industrial preparation of drugs. The catalyst could be recycled and reused at least ten times without any observable loss of its catalytic efficiency, mainly due to the covalently grafted {P2W15} cluster and high dispersion onto the γ-Al2O3 surface.Polyoxometalates (POMs) are a class of discrete anionic metal-oxides of V, Mo, W and Nb etc.

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Synthesis of nano-sized porous γ-alumina powder via a precipitation/digestion route

Cited by 136 publications

References 22 publications

Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

A simple and efficient approach for synthesis of 1,4-dihydro-pyridines using nano-crystalline solid acid catalyst

Covalent Immobilization of Polyoxotungstate on Alumina and Its Catalytic Generation of Sulfoxides

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