Polyethylenimine-Impregnated Mesoporous Delignified Wood with High Mechanical Strength for CO2/N2 Selective Adsorption

In this work, a high-strength, hierarchical, and mesoporous wood decorated with polyethylenimine (PEI) for CO2/N2 selective adsorption is studied. After lignin removal, the delignified wood showed micro- and mesoporous structures with a high specific surface area (44.3 m2/g; determined by physical adsorption). With increasing PEI loading content, the PEI-delignified wood composite with 49 wt % PEI (P49) showed superhigh CO2/N2 ideal selectivity (S = 114), a high CO2 adsorption capacity (2.96 mmol/g), and excellent CO2 cyclic performance at 120 °C. More importantly, the Young's modulus of P49 reached 756 MPa, that is, over 10 times higher than those of cellulose porous materials reported in the literature. This PEI-delignified wood can play an important role in combustion as a potential CO2 adsorbent.