Efficient room-temperature hydrolytic cleavage of CS₂via Pd-anchored polynitrogen porous polymers

Metal-loaded porous organic polymer (POP) catalysts show great promise for heterogeneous catalysis applications, particularly in pollutant degradation. We developed nitrogen-rich porous polymers (POPs 1a-1b) via Suzuki coupling between hexaazatriphenylene (HATN) and phenylboronic acid, creating high-surface-area frameworks ideal for sulfur pollutant adsorption. Subsequent Pd(II) immobilization through Pd-N coordination produced highly active catalysts (POPs 2a-2b) capable of room-temperature hydrolytic cleavage of carbon disulfide (CS₂) and carbonyl sulfide (COS). These catalysts demonstrated initial efficiencies of 7.81 and 4.93 μmol/g/h for POPs 2a-2b, respectively, over a 630-minute period. Remarkably, treatment with concentrated nitric acid enabled successful in situ regeneration and reuse. The combination of HNO₃ with a one-pot approach dramatically enhanced catalytic performance, achieving efficiencies of 67.77 and 177.50 μmol/g/h, representing a 36-fold improvement over standard conditions, which is the record-breaking intrinsic catalytic activity. During five consecutive desulfurization cycles, the catalysts maintained excellent stability, with two catalysts remained above 80 % and 92.7 %, respectively. Mechanistic studies using in-situ DRIFTS and DFT calculations revealed that hydroxide ions (OH⁻) nucleophilically attack the carbon atoms in coordinated CS₂ and COS, resulting in CS bond cleavage and subsequent formation of CO₂ and sulfide species. This work presents a highly efficient, recyclable heterogeneous catalytic system for environmental desulfurization.