This work demonstrates the potential use of triamine-grafted pore-expanded mesoporous silica TRI-PE-MCM-41, for the removal of CO2 from nitrogen, oxygen and water vapor-containingmixtures. In addition to unprecedentedly high CO2 uptake at low pressure, high adsorption rate and stability, this material exhibited very high selectivity for CO2 over N-2 and O-2, regardless of the presence of moisture. It is thus highly suitable for use in CO2 removal from air, for example in airpurification and in closed-circuit breathing systems. (C) 2010 Elsevier Ltd. All rights reserved.