A novel approach for the preparation of highly stable Pd membrane on macroporous α-Al2O3 tube

Pd membrane with excellent stability was prepared on macroporous α-Al2O3 tubes using a nanoporous Sil-1 zeolite as an intermediate support and diffusion barrier layer. The detailed microstructure of the composite membrane was examined by scanning electron microscopy and mapped by EDXS and EPMA to reveal a palladium membrane anchored by multi-legs Pd protrutions that penetrates through the interstices of the zeolite grains into the seed layer. This membrane architecture allowed the membrane to tolerate rapid and repeated cycling of gases, temperature and pressure over 300 h without lost of permeance and selectivity. The zeolite layer contributed up to 25% of the transport resistance across the Pd–Sil-1 composite membrane and has a significant effect on the hydrogen permeance.

Research highlights▶ Pd membranes with excellent stability were successfully prepared on macroporous α-Al2O3 tubes. ▶ Nanoporous Sil-1 zeolite was used as an intermediate support and diffusion barrier. ▶ Pd membrane was anchored by multi-legs Pd protrutions. ▶ Pd membrane can tolerate repeated cycling of gases, temperature and pressure.