ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Coprecipitation synthesis of Si-modified mesoporous alumina with high thermal stability from coal fly ash

Yusheng Wu, Laishi Li, and Xu Yang

School of Materials Science and Engineering, Shenyang University of Technology, Shenyang, China

E-mail: wuyus@sut.edu.cn

Received: 31 October 2019  Accepted: 10 February 2020

Abstract:

Si-modified mesoporous alumina with high thermal stability was synthesized from coal fly ash through a facile coprecipitation method using NH₄HCO₃ and NH₄Al(SO₄)₂. The effects of Si dopant contents on the characterization of alumina were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, N₂ adsorption–desorption method and transmission electron microscopy. The results show that the introduction of Si effectively inhibits the phase transformation of mesoporous alumina from γ-Al₂O₃ to α-Al₂O₃. Compared with alumina obtained without Si dopant, the specific surface area of mesoporous alumina with adding 12 wt% Si improved from 5.2 to 227.5% by increasing the calcination temperature from 500 to 1200 °C, respectively. The specific surface area, pore volume and pore size of mesoporous alumina with 12 wt% Si calcined at 1100 °C are 149 m²/g, 0.52 cm³/g and 8.9 nm, respectively.

Keywords: Mesoporous alumina; Si dopant; Coal fly ash; Thermal stability; AACH

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01101-9

Chemical Papers 74 (8) 2537–2543 (2020)