There is a growing concern on the relationship between anthropogenic carbon dioxide and climate changes. A promising approach is the adsorption technology using mesoporous MCM-41 materials that can be easily synthesized to depict structures adequate to the flow of gas. The aim of this study was to improve the synthesis of MCM-41 using cationic surfactant mixtures and apply the resulting materials to CO 2 adsorption. To that end, the simplex-centroid design was applied to optimize CO 2 adsorption from seven mesoporous MCM-41 materials synthesized by the hydrothermal method using surfactants from hydrophobic chains of different sizes. The cationic surfactants used were tetradecyltrimetylammonium bromide, cetyltrimethylammonium bromide, trimethyloctadecylammonium bromide and their mixture at ratios of 1:1 and 1:1:1. The CO 2 adsorption was investigated using thegravimetric method at 298 K and pressures up to 40 bar. The resulting materials, labelled C 17 , C 19 , C 21 , C 17 C 19 , C 19 C 21 , C 17 C 21 and C 17 C 19 C 21 , were characterized by XRD, FTIR, TG and SEM and showed significant differences in structure as well as in the mass of CO 2 adsorption. The response models showed that the best combination of the surfactants resulted from C 17 C 19 sample, which presented synergistic interactions reaching the highest value of CO 2 adsorption (0.62 g CO 2 /g adsorbent), compared to other samples.