Efficient Separation of Methanol-to-Olefins Products Using a Robust Polycatenated Hydrogen-Bonded Organic Framework.

The methanol-to-olefins process produces mixtures of ethylene and propylene, driving demand for high-performance separation materials. We present HOF-ZJNU-3, a hydrogen-bonded organic framework built from an expanded BTB (4,4',4″-benzene-1,3,5-triyl-tribenzoate) linker, featuring the highest catenation degree observed in BTB-based HOFs. This unique architecture confers good stability under solvent, pH, and thermal conditions. With optimally sized pores and aromatic-rich surfaces, HOF-ZJNU-3 demonstrates excellent propylene/ethylene separation potential, outperforming its parent frameworks (HOF-BTB and HOF-BTB-NH2) under ambient conditions. Notably, the material accomplishes single-cycle purification of high-purity ethylene (99.95%) and propylene (99.5%) from equimolar binary mixtures, achieving a record ethylene productivity of 3.22 mol kg-1 among HOF adsorbents. This study not only establishes HOF-ZJNU-3 as a benchmark HOF material for MTO product separation but also advances the structural design of HOFs for industrial olefin purification.