Synthesis and characterization of three-dimensional interconnected large-pore mesoporous cellular lignin carbon materials and their potential for CO2 capture

Ordered mesoporous lignin carbons with large mesopore sizes and mesopore volumes were synthesized using lignin as a renewable and sustainable polymeric precursor and siliceous mesostructured cellular foam as a template in a solvothermal process. The prepared lignin carbon materials, which are present in arrays of mi-crospheres, showed a quasi-spherical porous morphology and were highly characterized by the rarely seen dominance of a three-dimensional large mesopore system that had a narrow pore size distribution centered at 20-25 nm with high surface areas of up to 960 m(2) g(-1) and mesopore volumes of up to 1.50 cm(3) g(-1), respectively. The results also showed that the large-pore mesoporous framework could be readily tuned by varying the carbonization/activation temperature and the silica-to-lignin ratio by mass. Applying the as-prepared carbon materials as porous support for preparing CO2 adsorbent materials demonstrated that the large-pore meso-structured carbon can effectively accommodate a large uploading capacity of polyamines, giving rise to a high CO2 uptake capacity of 129.9 mg-CO2/g-adsorbent or 2.95 mmol-CO2/g-adsorbent with favorable adsorption kinetics at 75 degrees C and a CO2 partial pressure of 0.15 bar, which is among the best sorbents ever reported under similar adsorption conditions.

Automated summary

Ordered mesoporous lignin carbons with large mesopore sizes and volumes were synthesized using lignin as a precursor and a siliceous mesostructured cellular foam as a template. The materials showed a quasi-spherical porous morphology with a dominant three-dimensional large mesopore system. The carbon materials exhibited high surface areas and mesopore volumes. They also demonstrated excellent CO₂ uptake capacity and adsorption kinetics, making them promising sorbents for CO₂ capture.