Chitosan-based porous carbon material with lamellar stacking structure for efficient CO2 adsorption and catalytic conversion

Porous carbon with a specially designed structure as a CO2 adsorbent and catalyst is an attractive research topic. In this work, a series of chitosan-based porous carbons were fabricated using polyethylene oxide-polypropylene oxide-polyethylene (P123) as structure-directing agent, and KOH, potassium citrate (KCA), K2CO3, or NaNH2 as activators through a combined hydrothermal and carbonization process. Structural characterization revealed that three-dimensional porous carbons (3D-NPCs) activated by NaNH2 possess a unique three-dimensional rounded square morphology with interlayer structures and high specific surface areas ranging from 742 to 1637 m2 center dot g-1. The 3D-NPCs exhibit excellent CO2 adsorption performance, achieving CO2 adsorption capacities of 5.92 mmol center dot g-1 at 273 K and 4.06 mmol center dot g-1 at 298 K. Moreover, the interlayer restriction in 3D-NPCs promotes CO2 adsorption and mass transfer, directly amplifying catalytic activity for the solvent-free CO2 cycloaddition reaction with epoxides. Furthermore, 3D-NPCs demonstrated outstanding recyclability as both adsorbents and catalysts, offering novel insights into the design of three-dimensional spatially structured porous carbon materials for CO2 adsorption and conversion.