Fabrication of the ( h 0 h )-Oriented Tubular MFI Zeolite Membrane via a Dual-Template Strategy Toward Butane Isomer and Ammonia Separation

The fabrication of highly (h0h)-oriented MFI zeolite membranes on scalable supports is critical for demanding energy-efficient separations, but remains a significant challenge. Herein, we reported a facile synergistic dual-template strategy to prepare an (h0h)-oriented MFI zeolite membrane on porous α-Al2O3 tubular substrates. By optimization of the molar ratio of tetrapropylammonium (TPA+) as the structure-directing agent and tetrabutylammonium (TBA+) as a growth modifier, the preferred orientation and grain boundary structure of the membranes could be precisely tailored. The optimized membrane exhibited an n-/i-C4H10 separation factor of 40.9 with an n-C4H10 permeance of 6.6 × 10–8 mol m–2 s–1 Pa–1. Moreover, the membrane demonstrated remarkable versatility and performance in ammonia (NH3) separation, achieving a high NH3/H2 separation factor of ∼100 with an NH3 permeance of 3.1 × 10–7 mol m–2 s–1 Pa–1. This work provides a practical route to high-performance-oriented MFI membranes for key separations in the energy and chemical industries.