Study on NiO excess in preparing NiAl2O4

Han, Yong Sheng; Li, Jian Bao; Ning, Xiao Shan; Yang, Xiao; Chi, Bo

doi:10.1016/j.msea.2003.11.026

Cited by 52 publications

(33 citation statements)

References 12 publications

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“…6(a) can be attributed to the formation of NiAl 2 O 4 . It should be mentioned that, the reaction temperature range observed is in good agreement with the reported ranges in literature [18,11].…”

Section: Mechanical Activation and Heat Treatmentsupporting

confidence: 91%

“…It is worth noting that one of the shortcomings of the solid state route is that at temperatures around 1200°C, the residual Al 2 O 3 dissolves into spinel structure and forms an Al 2 O 3 -NiAl 2 O 4 solid solution, which leads to the excess of NiO in final products [7,18]. Therefore, decreasing the solid state reaction temperature to less than 1100°C by 15 h mechanical activation eliminates the aforesaid problem.…”

Section: Mechanical Activation and Heat Treatmentmentioning

confidence: 99%

“…Also, reactivity of the milled powders can be enhanced by mechanical activation and hence, the temperature in subsequent heat treatment steps will be reduced [17]. In a previous work by Han et al [18], effect of excess NiO on the synthesis of NiAl 2 O 4 through solid state reaction was investigated. They found that the milling time and starting materials had an important effect on the excess of NiO.…”

Section: Introductionmentioning

confidence: 99%

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Preparation of nanostructured nickel aluminate spinel powder from spent NiO/Al2O3 catalyst by mechano-chemical synthesis

Nazemi

Sheibani

Rashchi

et al. 2012

Advanced Powder Technology

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a b s t r a c tIn this paper, the possibility of mechano-chemical synthesis, as a single step process for preparation of nanostructured nickel aluminate spinel powder from NiO/Al 2 O 3 spent catalyst was investigated. Powder samples were characterized in terms of composition, morphology, structure, particle size and surface area using complementary techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA) and volumetric adsorption of nitrogen. It was found that formation of spinel was possible after 60 h of milling with no heat treatment. Additionally, influence of mechanical activation on the heat treatment temperature was discussed. It was observed that heat treatment of 15 h milled sample at 1100°C is enough to produce nickel aluminate spinel. A product of direct mechanical milling showed higher value of surface area (42.3 m 2 /g) and smaller crystallite size (12 nm) as compared to the heat treated product.

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Section: Mechanical Activation and Heat Treatmentsupporting

confidence: 91%

Section: Mechanical Activation and Heat Treatmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Preparation of nanostructured nickel aluminate spinel powder from spent NiO/Al2O3 catalyst by mechano-chemical synthesis

Nazemi

Sheibani

Rashchi

et al. 2012

Advanced Powder Technology

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“…Furthermore, the X-ray patterns of the treated mixed solids calcined at 300 and 400°C showed a progressive decrease in the degree of crystallinity and crystallite size of catalytically active species of the system under investigation, as well as increasing of surface areas of the system upon doping with CeO 2 , and consequently increased the catalytic activity of the system under investigation. In other words, CeO 2 addition to NiO/ Al 2 O 3 system enhanced the nickel dispersion leading to a significant increase in the concentration of active sites via creation of new ion pairs which may improve catalytic activity [7,8,[22][23][24][25][26].…”

Section: Catalytic Activity Measurements Of Pure Nio/al 2 O 3 System mentioning

confidence: 99%

Effects of doping with CeO2 and calcination temperature on physicochemical properties of the NiO/Al2O3 system

Shaheen¹,

El-Hendawy

2009

Open Chemistry

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Abstract:The effects of doping with CeO 2 and calcination temperature on the physicochemical properties of the NiO/Al 2 O 3 system have been investigated using DTA, XRD, nitrogen adsorption measurements at -196°C and decomposition of H 2 O 2 at 30-50°C. The pure and variously doped solids were subjected to heat treatment at 300, 400, 700, 900 and 1000°C. The results revealed that the specific surface areas increased with increasing calcination temperature from 300 to 400°C and with doping of the system with CeO 2 . The pure and variously doped solids calcined at 300 and 400°C consisted of poorly crystalline NiO dispersed on γ-Al 2 O 3. Heating at 700°C resulted in formation of well crystalline NiO and γ-Al 2 O 3 phases beside CeO 2 for the doped solids. Crystalline NiAl 2 O 4 phase was formed starting from 900°C. The degree of crystallinity of NiAl 2 O 4 increased with increasing the calcination temperature from 900 to 1000°C. An opposite effect was observed upon doping with CeO 2 . The NiO/Al 2 O 3 system calcined at 300 and 400°C has catalytic activity higher than individual NiO obtained at the same calcination temperatures. The catalytic activity of NiO/Al 2 O 3 system increased, progressively, with increasing the amount of CeO 2 dopant and decreased with increasing the calcination temperature.© Versita Warsaw and Springer-Verlag Berlin Heidelberg.

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“…Nickel aluminate (NiAl 2 O 4 ) is a ternary oxide with AB 2 O 4 spinel structure, where A and B are cations occupying tetrahedral (Ni 2+ ) and octahedral (Al 3+ ) sites, respectively [1]. Due to its high mechanical resistance, as well as its high thermal and chemical stabilities, nickel aluminate has been employed as catalyst support in various chemical reactions such as 1, 2, 4-trichlorobenzene hydrodechlorination [2], partial oxidation of methane to syngas [3], CO 2 reforming of methane [4], chemical-looping combustion [5,6], acetylene hydrogenation [7], steam reforming of methane [8,9], combustion of methane [10] and steam reforming of glycerol to hydrogen production [11].…”

Section: Introductionmentioning

confidence: 99%

Effect of thermal treatment on the synthesis of NiAl 2 O 4 spinel oxide using chitosan as precursor

et al. 2015

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Nickel aluminate oxide (NiAl 2 O 4 ) was prepared using chitosan as polymeric precursor and ammonia solution as a precipitating agent. In addition, nickel nitrate and aluminum nitrate salts were used as sources of Ni and Al, under stoichiometric amounts (molar ratio Ni:Al = 1:2). NiAl 2 O 4 particles were prepared at different calcination temperatures and their properties were investigated. The synthesized materials were characterized by X-ray diffraction, infrared spectroscopy, atomic force microscopy, thermogravimetric analysis and nitrogen adsorption-desorption isotherms. The results showed that the thermal treatment process strongly influence on the formation of a single-phase structure of NiAl 2 O 4 spinel. Nickel aluminate spinel with a porous structure and high surface area was obtained at temperatures above 700 o C. Keywords: nickel aluminate, synthesis, characterization, chitosan, porous material. Resumo Aluminato de níquel (NiAl

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Study on NiO excess in preparing NiAl2O4

Cited by 52 publications

References 12 publications

Preparation of nanostructured nickel aluminate spinel powder from spent NiO/Al2O3 catalyst by mechano-chemical synthesis

Preparation of nanostructured nickel aluminate spinel powder from spent NiO/Al2O3 catalyst by mechano-chemical synthesis

Effects of doping with CeO2 and calcination temperature on physicochemical properties of the NiO/Al2O3 system

Effect of thermal treatment on the synthesis of NiAl 2 O 4 spinel oxide using chitosan as precursor

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