One-step synthesis of zinc-encapsulated MCM-41 as H2S adsorbent and optimization of adsorption parameters

The nano-sized structure of well-ordered Zn@MCM-41 adsorbent was synthesized through a direct hydrothermal method using CTAB as a structure-directing agent in an ammonia aqueous solution with different amounts of zinc acetylacetonate which were inserted into the structure-directing agent’s loop during the synthesis. The XRD, HRTEM, and N2 adsorption-desorption isotherms were used to characterize the prepared ZnO functionalized mesoporous silica samples. As a result, the presence of ZnO in highly-ordered MCM- 41’s pore was proved as well as maintenance of the ordered mesostructure of MCM-41. The materials were possessed with a high specific surface area (1114-509 m^2 g^-1) and a large pore diameter (4.03-3.27 nm). Based on the obtained results from the adsorption of H2S gas in a lab-made setup, the Znx@MCM-41 showed the superior ability to increase of ZnO amount up to 7 hours as a breakthrough point. A two factor (zinc percent and temperature) experimental design with three levels was accomplished to optimize the adsorption parameters. The influence of parameters and the interactions on the adsorption of H2S were studied and optimized. Also, the H2S breakpoint curves carried on by UOP163 method.