Glow discharge plasma-assisted template removal of SBA-15 at ambient temperature for high surface area, high silanol density, and enhanced CO ₂ adsorption capacity

Glow discharge plasma was successfully applied for effective removal of the organic template P-123 from SBA-15 ordered mesoporous silica at near-room-temperature (below 50°C) and in a short operation time (2 h). The as-made SBA-15 treated with glow discharge exhibited a larger surface area of 1025 m² g^-1 with larger pores and microspore volume as compared with that of conventional calcination (550°C and 5 h, 827 m ² g^-1). In addition to less structural shrinkage, the plasma-prepared SBA-15 showed significantly increased silanol density from 5.4 to 6.6-7.6 mmol g^-1, which led directly to higher amine loading from 1.8 to 3.0 mmol g^-1. Consequently, the plasma-treated sample showed 77% more CO₂ capacity and 60% higher CO₂/N₂ selectivity than the conventionally treated sample at 0.15 bar and 25°C. The advantage of using glow discharge plasma for low-temperature template removal for achieving enhanced performance for CO₂ adsorption is clearly demonstrated.