Moisture effect on the separation of CO2/CH4 mixtures with amine-functionalised porous silicas

• Moisture increases CO 2 adsorption in the material modified with a tertiary amine. 13 ssNMR and DFT methods provided molecular insights into mechanisms. Selectivity remarkably amine moisture. DFT/cluster calculations confirmed water effect on adsorption. The of minor amounts CH 4 primary secondary amine-functionalised mesoporous silicas (APTES@SBA-15 DEAPTES@SBA15, respectively) was studied combination high-pressure gas adsorption, solid state NMR labelled density functional theory (DFT) calculations. Known were pre-adsorbed materials (0.047 to 0.157 mmol?g ?1 ) performance for compared dry samples. We observed that even when only are present, revealed significant enhancement selectivity (from ca . 5.8 208) while one maintained same properties. This is related change mechanism DEAPTES@SBA15 present since participates reaction produce bicarbonate (confirmed by results). Such species not APTES@SBA-15 water. From broader perspective, results presented this work relevant confirm suitability type hybrid adsorbents industrial applications where may be process streams, such as during bio, landfill, or natural upgrading, also carbon capture applications.