(289a) Design of Organically Modified Silicas for Carbon Dioxide Adsorption

Periodic mesoporous silica materials, such as MCM-41, have good adsorption characteristics due to their high porosity and surface area. The addition of organic surface groups offers the possibility of tailoring the adsorbent for particular applications. In this work, the use of organically modified MCM-41 for separation of CO2 from flue gases has been investigated. Atomistic models of MCM-41 have been created based on a kinetic Monte Carlo (kMC) simulation method [1]. The polymerisation of the silicic acid in the presence of the templating micelles and the subsequent calcination step are simulated following the real synthesis path. The pore surface of the resulting silica is then modified by substituting surface hydroxyl groups by organic groups. The influence of the structure and the concentration of the surface group as well as the pore size on the adsorption has been investigated by grand canonical Monte Carlo (GCMC) simulation of adsorption. Simulated and experimental isotherms show good agreement for CO2 and other gases. In our presentation, we demonstrate how this combination of kMC simulation of materials synthesis and GCMC simulation of adsorption can be used as an adsorbent design tool.

[1] Schumacher, C.; Gonzalez, J.; Wright, P. A.; Seaton, N. A., Generation of atomistic models of periodic mesoporous silica by kinetic Monte Carlo simulation of the synthesis of the material. Journal Of Physical Chemistry B 2006, 110, (1), 319-333.