SO/NO Separation Driven by NO Dimerization on SSZ-13 Zeolite Membrane.

The molecular state is crucial for precise gas separation using a zeolite membrane, yet the state control remains a big challenge. Herein, we report a NO dimerization facilitated high performance SO/NO separation on a SSZ-13 zeolite membrane. The NO dimerization is triggered by temperature and pressure to form NO with big molecular size, and NO diffusion into the zeolite pore is inhibited on the basis of size exclusion, leading to high separation selectivity. Consequently, SO rather than NO preferentially permeates through the SSZ-13 membrane with a high SO permeance of 2 × 10 mol m s Pa and high SO/NO separation factor of 22, ∼50-fold of that measured without dimerization. The dimerization effect for SO/NO separation prevails in other small-pore zeolites such as NaA. This advanced function is revealed through membrane separation using single and mixture gases.