Mild Fabrication of Highly (h0 h)-Oriented MFI Zeolite Membrane from Self-Pillared Nanosheets Toward Superior Butane Isomer and Ammonia Separation

Abstract

Mild fabrication of (h0 h) preferentially oriented MFI zeolite membrane, which has been proven advantageous for high-efficiency n-/i-butane isomer separation, remains a grand challenge. In this study, the preparation of highly (h0 h)-oriented MFI zeolite membrane is achieved through combining self-pillared pentasil (SPP) nanosheet seeds with single-mode microwave heating. Benefiting from the unique geometry and hierarchical structure, both preferred orientation and grain boundary structure of MFI zeolite membranes can be deliberately controlled under mild reaction conditions. Gas permeation results imply that obtained membrane exhibit n-/i-C₄H₁₀ separation factor of 55.2 with n-C₄H₁₀ permeance of 2.55 × 10^⁻7 mol m⁻² s⁻¹ Pa⁻¹, surpassing the performance of state-of-the-art MFI zeolite membranes produced via solution-based synthetic protocol; simultaneously, its NH₃/H₂ and NH₃/N₂ separation factor reaches as high as 353.8 and 1362.2 with NH₃ permeance of ≈1.2 × 10⁻⁶ mol m⁻² s⁻¹ Pa⁻¹, showing great promise for energy-efficient NH₃ separation during Haber-Bosch process.