In this work MgO/Al2O3 nanocomposites with weight ratios from 5% to 25% were synthesized by precipitation-impregnation method and their structural properties were characterized. In the next step, the capability of the nanocomposites in H2S removal compared to Mg-Al spinel (MgAl2O4), synthesized through ion-pair complex precursor route and alumina samples, prepared via sol-gel precipitation methods, was investigated. The results indicated that among the studied sorbents Mg-Al spinel presents a distinctly higher H2S removal. In addition, the MgO/Al2O3 nanocomposites compared to the alumina sorbents, exhibited much better performance in H2S removal. Also CO2-TPD analysis reveals higher amounts of basic sites for Mg-Al spinel compared to 25 wt% MgO/75 wt% Al2O3 nanocomposite. (c) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.