Graphene oxide and palladium-coated ceramic hollow fiber membranes for effective hydrogen permeation

Although palladium (Pd) membranes present high selectivity towards hydrogen (H 2 ), industrial applications are limited mainly due to the membrane cost and stability. Graphene oxide (GO) membranes have shown promise application for gas separations due to their unique properties, including high permeability and chemical and thermal stabilities. The assembly of composite Pd and GO membranes on porous substrates represents a suitable alternative for the synergistic application of these materials for gas separations. Herein, we investigated the application of composite Pd/GO membranes deposited on the outer surface of asymmetric alumina (Al 2 O 3 ) hollow fibers. The GO membrane was applied to have the dual function of selective H 2 permeance and to decrease the roughness of the substrate surface for further Pd deposition. The GO-coated membrane presented H 2 permeance of 2452 ± 14 GPU and H 2 /N 2 selectivity of 5.57 ± 0.17 at 120 kPa. The Pd plating deposition time was changed in 30 and 60 min, resulting in Pd membranes with thicknesses of 0.83 ± 0.09 and 1.09 ± 0.10 µm, respectively. Both composite Pd/GO membranes presented infinity H 2 /N 2 selectivity, and the 30- and 60-minute Pd deposited membranes presented H 2 permeance of 592 ± 2 and 1060 ± 16 GPU, respectively, at 120 kPa. Therefore, the increase in the Pd deposition time favored the H 2 diffusion through the metallic Pd layer and improved the H 2 permeance. Thus, composite Pd/GO membranes with tunable molecular sieving perm-selectivity are proposed for H 2 separations.