A Novel Synthesis Route of Mesoporous γ-Alumina from Polyoxohydroxide Aluminum

Segal, Felipe Módolo; Corrêa, Michelle Fidelis; Bacani, Rebeca; Castanheira, Bruna; Politi, Mário José; Brochsztain, Sergio; Triboni, Eduardo Rezende

doi:10.1590/1980-5373-mr-2017-0674

Cited by 40 publications

(14 citation statements)

References 59 publications

(77 reference statements)

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“…This shows that the synthesis of alumina catalyst calcined at 700°C did not change the peak position of the diffractogram; therefore, there was similarity in the phase structure of the γ-alumina crystals produced. This is in accordance with the results obtained by Segal et al (2018), who found that gamma alumina (Al-Al2O3) synthesized at 700ºC had good crystallinity. Sun et al (2008) and Hartmann et al (2012) also revealed that alumina samples calcined at 500°C and 800°C had peak characteristics with small and narrow angles, indicating that the properties and structure of the sample persisted during calcination.…”

Section: Characterizationsupporting

confidence: 93%

Triacetin Production From Glycerol Using Heterogeneous Catalysts Prepared From Peat Clay

Yanti¹,

Hesty²,

Putra³

et al. 2019

IJTech

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Glycerol, an abundant by-product of biodiesel production, is urgently considered to increase its usage. Triacetin produced from glycerol is an important material, used in polyester, cryogenics, cosmetics and as a biodiesel additive. Using homogeneous catalysts in triacetin production involves high product separation costs. The purpose of this study is to synthesize heterogeneous catalysts based on alumina and silica from peat clay for use in the production of triacetin from glycerol. The conversion of glycerol for triacetin production using such alumina and silica catalysts yielded levels of 82.7% and 87.4%, respectively. These values were greater than the conversion value of 71.2% using a sulfuric acid homogeneous catalyst. An optimum conversion of 91% was obtained at the mole ratio of glycerol to acetic acid of 8.9. The potential heterogeneous catalysts were confirmed by the results of SEM, XRD and BET characterization. Therefore, the production of triacetin using heterogeneous silica catalyst could be an alternative approach in commercial processes which currently using homogeneous catalysts.

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Section: Characterizationsupporting

confidence: 93%

Triacetin Production From Glycerol Using Heterogeneous Catalysts Prepared From Peat Clay

Yanti¹,

Hesty²,

Putra³

et al. 2019

IJTech

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show abstract

“…The phase analysis confirmed the presence of gamma alumina phase in the two tested samples. Similar results published for γ-Al2O3 by [61][62][63][64].…”

Section: X-ray Diffraction (Xrd) Analysissupporting

confidence: 87%

Aluminum Building Scrap Wire, Take-Out Food Container, Potato Peels and Bagasse as Valueless Waste Materials for Nitrate Removal from Water supplies

2018

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Purpose Two types of active acidic alumina derived from aluminum building wire scraps (AlBWS) and aluminum takeout food container waste (AlTFC), as well, two effective types of activated carbon prepared from potato peels (ACPP) and sugarcane bagasse (ACSB) for removal of nitrate ions were utilized in this study. Methods Adsorbent samples were prepared with highly porous structure and large specific surface area above 200 m 2 g −1. Also, low calcinations temperatures and low-priced chemicals were used. Results The results showed that the adsorption of nitrates were rapid. The q max were found to be 12.4, 8.8, 7.1 and 3.9 (mg g −1) for AlTFC, AlBWS, ACPP and ACSB samples, respectively. The thermodynamic parameters showed the endothermic nature and adsorption of nitrate ions and are considered chemisorption. The total cost of the samples production were 13 USD kg −1 for acidic alumina and 6 USD kg −1 for active carbon. Conclusion The adsorption of nitrates were utilized in real and synthetic samples which give an excellent removing capability for nitrate pollution from groundwater samples.

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“…And the island-like particles are connected and grow in the form of a thick plate for the film deposited on Al200HT (Figure 5(b)). In the film deposited on Al500HT, a cauliflower-like structure, which was found in the γ-Al 2 O 3 or β-Ga 2 O 3 samples, is further formed [55] [56].…”

Section: Electrodeposition and Characterizationmentioning

confidence: 97%

Effect of Heat Treatment of Al Substrate on GaN Film Electrodeposited in Aqueous Solution

Kang¹,

Kuroda²,

Okido³

2020

JSEMAT

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Most reports on the fabrication of high-quality Gallium nitride (GaN) are typically based on physical techniques that require very expensive equipment. Therefore, the electrodeposition was adopted and examined to develop a simple and economical method for GaN synthesis. GaN films are synthesized on aluminum substrates that are heat-treated at various temperatures using a low-cost and low-temperature electrochemical deposition technique. The electrochemical behavior of source ions in aqueous solutions is examined by cyclic voltammetry (CV). In the solution at pH 1.5 containing 0.1M Ga(NO 3 ) 3 , 2.5 M NH 4 NO 3 and 0.6 M H 3 BO 3 , reduction of gallium and nitrate ions are observed in CV. The presence of hexagonal GaN and gallium oxide (Ga 2 O 3 ) phases is detected for the films deposited on Al substrates at −3.5 mA•cm -2 for 3 h. The energy dispersive X-ray and mapping results reveal that Ga, O, and N coexist in these films. Raman analysis shows hexagonal GaN formation on Al substrates. The changes in the morphology and preferred orientation of GaN were found, which was caused by the reactivity of aluminum surface and the aluminum oxide layer formed by the heat treatment.

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A Novel Synthesis Route of Mesoporous γ-Alumina from Polyoxohydroxide Aluminum

Cited by 40 publications

References 59 publications

Triacetin Production From Glycerol Using Heterogeneous Catalysts Prepared From Peat Clay

Triacetin Production From Glycerol Using Heterogeneous Catalysts Prepared From Peat Clay

Aluminum Building Scrap Wire, Take-Out Food Container, Potato Peels and Bagasse as Valueless Waste Materials for Nitrate Removal from Water supplies

Effect of Heat Treatment of Al Substrate on GaN Film Electrodeposited in Aqueous Solution

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