Carbon dioxide adsorbs reversibly on a silica gel containing 3-aminopr
opyl groups bonded to surface atoms of silicon. These act as the activ
e sites for the chemisorption of CO2 at room temperature which is libe
rated by temperature programmed desorption at about 100 degrees C. The
material is capable of adsorbing about 10 STP cm(3) of dry CO2 per gr
am and can be regenerated upon heating. It might be used as scrubber f
or carbon dioxide from industrial gaseous streams. Adsorption of humid
CO2 produces a small amount of formaldehyde which suggests activation
of the carbon dioxide molecule.