Adsorption of CO2 on chitosan modified CMK-3 at ambient temperature

An ordered mesoporous carbon CMK-3 was synthesized by the template method, and was used to adsorb CO2. The synthesized CMK-3 was modified by immersion with chitosan solution to introduce surface nitrogen-containing functional groups. The effect of CMK-3 surface modification on CO2 uptake capacity was investigated. The texture characteristics of the CMK-3s were determined by small angle X-ray scattering analysis (SAXS), transmission electron microscope (TEM) and nitrogen adsorption analysis. The surface functional groups of the CMK-3s before and after modification were determined by an X-ray photoelectron spectroscope (XPS). CO2 uptake capacity of the CMK-3s was obtained by a gravimetric adsorption apparatus at room temperature under atmospheric pressure. Experimental results revealed that both nitrogen functional groups (pyridine and pyrrole) and supermicropores (<1.0 nm) of the chitosan modified CMK-3s after activation obviously increased. A remarkable enhancement of about 30% was obtained in CO2 adsorption at ambient temperature by the activated chitosan modified CMK-3 over the pristine one.

► Chitosan modified CMK-3 was synthesized as a CO2 adsorbent.
► Micropore volume of chitosan modified CMK-3 was increased after activation.
► CO2 adsorption capacity of the activated chitosan modified CMK-3 is enhanced.
► Both supermicropore and nitrogen-containing groups result in CO2 uptake capacity enhancement.