Chitosan-based monolithic carbon materials (CBMCMs) with three-dimensional macro-porous honeycomb structure have been prepared by coupling ice templating process with a low-temperature heat treatment one

of which the adsorption and regeneration performance for trace SO2 in air were evaluated.It is found that formation of macro-porous structure can be tuned by varying the freezing time

and low temperature pyrolysis

such as 200℃

favors the retain of abundant surface nitrogen functional group in as-made CBMCMs.After ion-exchange treatment in ammonia solution

the adsorption capacity for trace SO2 of the CBMCMs is greatly enhanced

as high as 57 mg·g-1.The exhausted CBMCMs can be partially regenerated simply by air purge at room temperature.The unrecoverable part is due to the formation of ammonium salts from protonated amine group and sulfite and sulfate ions

as the product of irreversible adsorption.It is believed that after further optimization

the CBMCM materials reported here will be of potential in air cleaning for efficient removal of SOx species

especially for cathode air desulfurization in proton exchange membrane fuel cells.