Synergistic approach to high-performance ultra-thin supported Pd-based membranes: Sacrificial graphene oxide interlayer and vacuum-assisted dip-coating

Abstract

Pd-based membranes are essential for the separation of hydrogen, and the performances of these membranes are largely determined by their thickness. In this study, a sacrificial graphene oxide (GO) interlayer and vacuum-assisted (V) dip-coating process were used synergistically to prepare ultra-thin Pd–Ag–Cu-based membranes that were deposited on an ultra-thin γ-Al2O3 film-coated porous α-Al2O3 hollow fiber support. For comparison purposes, Pd-, Pd–Ag-, and Pd–Cu-based membranes were also prepared using identical advanced procedures. The H2 flow of the newly developed advanced composite membranes produced by this work was then examined for temperatures in a range of 350–450 °C. The high-performance ultra-thin Pd-, Pd–Ag-, Pd–Cu-, and Pd–Ag–Cu-based hollow fiber membranes were assessed by comparison with both traditionally prepared membranes and previous results. An extraordinary H2 flux in the order of 119.53 mL/cm2 min has been obtained for a 1.43 μm-thickness Pd–Ag–Cu-based (V) γ-Al2O3/GO/α-Al2O3 hollow fiber membrane at 450 °C. The advanced ultra-thin Pd–Ag–Cu-based membranes not only have very high permeance but can maintain their performance stability for more than one day of exercise at 450 °C.