Design of Porous Aromatic Frameworks for Adsorptive Desulfurization: Synergistic Modulation via π-π Interactions and Mesopores.

The elimination of thiophenic sulfides from fuel oils is essential for both environmental protection and industrial catalysis. However, conventional hydrodesulfurization encounters difficulties due to severe operating conditions and limited efficacy against aromatic heterocyclic sulfur compounds. Adsorptive desulfurization offers notable advantages under milder conditions. In this investigation, topology-guided pore engineering was utilized to fabricate porous aromatic frameworks (PAFs) with distinct pore structures through Suzuki-Miyaura cross-coupling. Notably, PBPAF-2, despite its lower specific surface, demonstrates significantly improved mass transfer kinetics attributed to its unique mesoporous channel (2.13 nm), resulting in notably prolonged dynamic breakthrough retention times compared to other materials in the series. Analysis using synchrotron-assisted FT-IR spectroscopy reveals a blue-shift in benzene ring characteristic peaks following adsorption of dibenzothiophene and benzothiophene, indicating that π-π interactions between electron-rich aromatic rings in PAFs and thiophenic rings are the primary driving force for adsorption. This work proposes a dual-factor synergistic design strategy of "mass transfer optimization-electron cloud matching", offering a new strategy for the development of highly efficient adsorbents.