Surface-engineered porous aromatic framework enables a monolithic aerogel for high-efficiency benzene adsorption

Transforming fragile porous powders into robust, engineered monoliths without compromising the major porosity remains a key challenge. Herein, we address this by developing a surface-selective modification strategy that grafts aldehyde groups solely onto the external surface of porous aromatic framework-1 (PAF-1), yielding S-PAF-1-CHO. This modification preserves its pristine 1.4 nm micropores while enabling covalent integration with chitosan via Schiff-base chemistry to form lightweight aerogels with a high S-PAF-1-CHO loading. The resulting monolithic sorbent maintains a high specific surface area, great mechanical stability and achieves an exceptional benzene adsorption capacity of 5.98 mmol g^-1 (2000 ppm). This work establishes a versatile paradigm for converting high-capacity porous powders into practical, shaped sorbents through precise interfacial engineering.