Influence of the Obtaining Method on the Properties of Amorphous Aluminum Compounds

Mukhamed’yarova, Aliya N.; Nesterova, Oksana V.; Boretsky, Kirill S.; Skibina, Juliya D.; Boretskaya, A. V.; Egorova, S. R.; Ламберов, А. А.

doi:10.3390/coatings9010041

Cited by 11 publications

(7 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is generally known that ammonia adsorption on the alumina surface is originated from acid-base interactions between base ammonia adsorbate and acidic surface. In other words, the chemical characteristics and surface properties of alumina adsorbents significantly influenced the adsorption performance [5,40,41]. Since ammonia molecules can be adsorbed on both Bronsted acidic centers (Al-O − ) and Lewis acidic sites (Al (+) ) of the alumina surface, it is important to control both acidic centers to achieve enhanced adsorption performance.…”

Section: Resultsmentioning

confidence: 99%

Bead-Shaped Mesoporous Alumina Adsorbents for Adsorption of Ammonia

Kim

Lee

et al. 2020

Materials

View full text Add to dashboard Cite

It is of great importance to remove toxic gases by efficient methods for recovering the atmosphere to safe levels. The adsorption of the toxic gas molecules on solid adsorbents is one of the most useful techniques because of its simple operation and economic feasibility. Here, we report the uniform Bead-Shaped Mesoporous Alumina (BSMA) with tunable particle size for use as an adsorbent for removal of toxic ammonia. The BSMA particles with tunable diameters were synthesized by means of a sol-gel reaction of Al(NO 3 ) 3 ·9H 2 O as an alumina precursor in the presence of chitosan as a template. When the ammonia solution is added dropwise to the prepared viscose mixture containing chitosan, acetic acid, and the alumina precursor solution, the sol-gel condensation reaction of the alumina precursor occurs in the chitosan polymer metrics, resulting in bead-shaped chitosan-aluminum hydroxide particles. Then, final Bead-Shaped Mesoporous Alumina (BSMA) particles are obtained by calcination at a high temperature. During the synthesis, changing the mole ratio of the chitosan template to the alumina precursor allowed the particle diameter of the final bead sample to be finely controlled. In addition, the prepared BSMA particles have well-developed mesoporous characteristics with relatively large surface areas, which are beneficial for adsorption of gas molecules. In an ammonia adsorption experiment, the BSMA-1.5 sample, which has the smallest particle diameter among the bead samples, was the best in terms of adsorption capacity. In this manuscript, we systemically discuss the relationship between the characteristics of BSMA samples and their adsorption of ammonia. people can smell ammonia without significant symptoms at a level as low as 10 ppm, breathing 50-100 ppm of NH 3 can give rise to eye, throat, and nose irritation [12]. More severely, prolonged exposure at concentrations higher than 300 ppm can lead to either permanent damage to the body or even death. Therefore, the release of ammonia gas into the atmosphere must be controlled at a suitable level defined by Pollution Prevention and Control (PPC) regulations [13,14].To remove toxic ammonia molecules, there have been many techniques, including catalytic decomposition, combustion, absorption by solution, and adsorption by solids, employed in not only fundamental studies but also practical processes. Among the above techniques, the adsorption of ammonia on solid adsorbents has been widely studied because of the simple operation of the whole process and the easy regeneration of this valuable gas. To date, various porous materials, including activated carbon, zeolite, alumina, and a metal-organic framework (MOF), have been demonstrated as adsorbents for efficient ammonia removal, and there has been remarkable progress on adsorption of ammonia in terms of either adsorption capacity or adsorption kinetics [5,6,[15][16][17][18][19]. Helminen et al. studied the ammonia adsorption capacities of traditional inorganic adsorbents including activated carbon, alumina, silica gel, ...

show abstract

Section: Resultsmentioning

confidence: 99%

Bead-Shaped Mesoporous Alumina Adsorbents for Adsorption of Ammonia

Kim

Lee

et al. 2020

Materials

View full text Add to dashboard Cite

show abstract

“…At the same time, some authors [34,55,66] show a positive effect of heterogeneous catalysts during hydrothermal treatment of amorphous aluminum. For example, the hydrothermal treatment of pseudoboehmite, which contains the amorphous aluminum, significantly increases the selectivity and conversion of the alumina catalyst for skeletal isomerization of n-butylene to isobutylene [66].…”

Section: The Role Of Amorphous Aluminum Compounds In Petrochemistrymentioning

confidence: 90%

“…The study of amorphous aluminum compounds by physical and chemical methods is complicated because of their disordered structure. Thus, the diffraction patterns of amorphous aluminum compounds are usually characterized by a broad halo in the range of 2θ 20-40 • [33,34]. At the same time, the authors [34] pointed out a diffuse intense peak at 2θ = 8 • , which appears in the diffractograms of the gel-like precipitated products using nitrate-ammonia technology at a low pH = 5.…”

Section: Mode Of Productionmentioning

confidence: 98%

“…Thus, the diffraction patterns of amorphous aluminum compounds are usually characterized by a broad halo in the range of 2θ 20-40 • [33,34]. At the same time, the authors [34] pointed out a diffuse intense peak at 2θ = 8 • , which appears in the diffractograms of the gel-like precipitated products using nitrate-ammonia technology at a low pH = 5. Moreover, infrared spectroscopy (IR) identifies amorphous aluminum compounds by broad absorption bands of the deformation vibrations Al-O of a hexacoordinated aluminum atom in an oxygen environment (AlO 6 ) and OH-groups at 530-570 and 3470 cm −1 , respectively [35][36][37][38][39][40].…”

Section: Mode Of Productionmentioning

confidence: 98%

“…The phase transformations of amorphous aluminum compounds during thermal decomposition differ from the transformations of crystalline hydroxides by the intermediate stage-a formation of stable phase of amorphous alumina before crystallization into γ-Al 2 O 3 [33,34]. However, the temperature ranges of phase transitions from amorphous aluminum compounds into amorphous oxide and further into γ-Al 2 O 3 have not been clearly determined.…”

Section: Mode Of Productionmentioning

confidence: 99%

See 2 more Smart Citations

A Review on the Role of Amorphous Aluminum Compounds in Catalysis: Avenues of Investigation and Potential Application in Petrochemistry and Oil Refining

et al. 2021

View full text Add to dashboard Cite

Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.

show abstract