Synthesis, Characterization and Phase Transition of Highly Porous γ -Alumina Nanoparticles

  • S.D.N.S. Peiris
  • A.C.A. Jayasundera
Keywords: γ-Alumina, Alumina Nanoparticles, Phase Transitions of Alumina


Alumina is an important metal oxide used in a wide range of applications. It is a challenge to synthesize stable γ-alumina nanoparticles because, γ-phase of alumina is not as stable as α phase of alumina. But γ-alumina owns a higher surface area making it a good candidate for many industrial applications such as catalyst, catalytic support for petroleum refining, absorbent, alcohol dehydration, catalytic reduction of automotive pollutants like NOx, CO and hydrocarbons. This research focuses on synthesis, characterization and study of phase identification of pure γ-alumina nanoparticles.

Modified “Pechini method”(Danks, Hall, and Schnepp (2016); Huízar-Félix, Hernández, de la Parra, Ibarra, & Kharisov, 2012; Naskar, 2010; Zaki, Kabel, & Hassan, 2012)was used for the synthesis. Transesterification of citrate and ethylene glycol makes a covalent polymer network with trapped Al atoms. Continuous stirring of the reaction mixture while maintaining an optimum temperature is an important factor affecting this reaction. Calcination was carried out at different temperatures to identify phase transitions of alumina nanoparticles. In order to further reduce the particle size and increase the surface area, reactant ratio of citric acid: aluminum acetate was modified to 1:1, volume of ethylene glycol was increased up to 90% of volume of the solution and Triton X was used as a surfactant.

PXRD confirmed the pure γ-alumina phase (JCPDS No. 00-010-0425) in samples calcined at 900 °C. At 1000 °C γ-alumina is converted to α-alumina (JCPDS No. 00-083-2080). After the modifications, γ-alumina was identified at 700 °C. FTIR-ATR analysis shows peaks around 1127 cm-1 indicating the presence of Al-O-Al asymmetric bending modes and the peaks around 500 cm-1-750 cm-1 correspond to γ-AlO6 octahedral sites and 800 cm-1 correspond to AlO4 tetrahedral sites in γ alumina spinel structure. Resulted product of low temperature, pure γ-alumina nanoparticles will facilitate the industrial development in various applications.


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Danks, A. E., Hall, S. R., & Schnepp, Z. (2016). The evolution of "sol–gel‟ chemistry as a technique for materials synthesis. Materials Horizons, 3(2), 91-112. doi: 10.1039/c5mh00260e

Huízar-Félix, A. M., Hernández, T., de la Parra, S., Ibarra, J., & Kharisov, B. (2012). Sol–gel based pechini method synthesis and characterization of sm1−xcaxfeo3 perovskite 0.1≤x≤0.5. Powder Technology, 229, 290-293. doi: 10.1016/j.powtec.2012.06.057

Naskar, M. K. (2010). Soft solution processing for the synthesis of alumina nanoparticles in the presence of glucose. Journal of the American Ceramic Society, 93(5), 1260 – 1263 doi: 10.1111/j.1551-2916.2009.03555.x

Navrotsky, A. (2003). Energetics of nanoparticle oxides: interplay between surface energy and polymorphism. Geochemical Transactions, 4(1). doi: 10.1186/1467-4866-4-34

Trueba, M., & Trasatti, S. P. (2005). γ-Alumina as a support for catalysts: a review of fundamental aspects. Berichte der deutschen chemischen Gesellschaft (17), 3393 – 3403.

doi: 10.1002/ejic.200500348

Zaki, T., Kabel, K. I., & Hassan, H. (2012). Using modified pechini method to synthesize α-al2o3 nanoparticles of high surface area. Ceramics International, 38(6), 4861-4866. doi: 10.1016/j.ceramint.2012.02.076

How to Cite
S.D.N.S. Peiris, & A.C.A. Jayasundera. (2020). Synthesis, Characterization and Phase Transition of Highly Porous γ -Alumina Nanoparticles. International Journal for Research in Applied Sciences and Biotechnology, 7(1), 7-12.