Fast and low-temperature elimination of organic templates from SBA-15 using dielectric barrier discharge plasma

Organic templates P-123 of mesoporous SBA-15 can be effectively removed in a few minutes (4 min) by using the dielectric-barrier discharge (DBD) plasma technique at ambient pressure and low gas temperature (around 130 °C). The mesoporous SBA-15 was characterized by FT-IR, ²⁹Si solid sate NMR, TEM, XRD, TGA and N₂ adsorption/desorption isotherms. The as-made SBA-15 treated with DBD plasma exhibited a larger surface area of 790 m² · g⁻¹ with larger pores and microspore volume than samples prepared by using the conventional thermal calcination method (550 °C and 5 h, 660 m² · g⁻¹). In addition to less shrinkage of the silica framework, the DBD-prepared SBA-15 showed significantly increased weight loss of 8.3% about 200 °C as compared with that of conventional calcination (5.5%), which is attributed mainly to the dehydroxylation by condensation of silanol groups. (research note)