Ultra thin Pd membrane on α-Al2O3 hollow fiber by electroless plating: High permeance and selectivity

The morphology of Al2O3 hollow fiber has been systematically tuned by varying both the internal and external coagulants as well as the calcination temperature in order to enhance the mechanical strength and improve the surface property of the Al2O3 hollow fiber. The bending test and SEM results show that the finger-like void-free Al2O3 hollow fiber calcined at 1500 °C possesses not only very high bending strength but also uniform surface. The Al2O3 hollow fiber has also been successfully employed as a substrate to form an ultra thin Pd membrane by electroless plating without any modification process. The permeation test shows that this ultra thin Pd membrane supported on the Al2O3 hollow fiber substrate exhibits high permeance and selectivity for separation of hydrogen from a hydrogen/nitrogen mixture.