Chitosan-Based Porous Carbon Materials with Built-In Lewis Acid Boron Sites for Enhanced CO2 Capture and Conversion via an Electron-Inducing Effect

Electron-induced effects, which are prevalent in adsorption and heterogeneous catalytic reactions, can significantly influence the state and uptake of adsorbates. Here, we demonstrate the in situ doping of electron-deficient boron into the backbone of chitosan-based porous carbon materials. Despite a reduction in specific surface area, the resulting boron-doped porous carbons (NBPCs) exhibit an enhanced CO2 adsorption performance, with sample NBPC-10 achieving CO2 adsorption capacities of 7.62 and 4.82 mmol·g–1 at 273 and 298 K, respectively. This improvement is attributed to the electron-induced effect of boron doping, which also enhances the separation selectivity of CO2 from N2. Additionally, the high CO2 adsorption capacity fosters synergism between NBPCs and the cocatalyst tetrabutylammonium bromide (TBAB), thereby augmenting the catalytic activity for the cycloaddition of CO2 and epoxide. Notably, cyclic carbonate yields exceeding 99% were attained even under 1 bar of CO2. Controlled experiments corroborated the pivotal role of boron-doping-induced modifications in the porous carbon structure in enhancing both CO2 selective adsorption and conversion performance. Furthermore, NBPCs demonstrated excellent recyclability as both adsorbents and catalysts, offering fresh perspectives for the design of functionalized porous carbon materials tailored for CO2 capture and conversion.