Pd-Cu alloy membrane deposited on CeO2 modified porous nickel support for hydrogen separation

In this study, the hydrogen permeation behavior of a Pd-93-Cu-7 alloy membrane deposited on ceria-modified porous nickel support (PNS) was evaluated. PNS, which has an average pore size of 600 nm, was modified by alumina sol. Alumina sol was prepared using precursors that had a mean particle size of 300 nm. Alumina-modified PNS was further treated with ceria sol modification to produce a smoother surface morphology and narrow surface pores. A 7 mu m thick Pd-93-Cu-7 alloy membrane was made on an alumina-modified PNS and a ceria-finished membrane was fabricated by magnetron sputtering followed by Cu-reflow at 700 degrees C for 2 h. SEM analysis showed that the membrane deposited on a ceria-finished PNS contained more clear grain boundaries than the membrane deposited on the alumina-modified PNS. The membrane was mounted in a stainless steel permeation cell with a gold-plated stainless steel O-ring. Permeation tests were then conducted using pure hydrogen and helium at temperatures ranging from 673 to 773 K and feed side pressures ranging from 100 to 400 kPa. These tests showed that the membrane had a hydrogen permeation flux of 2.8 x 10(-1) mol m(-2) s(-1) with H-2/He selectivity of >50,000 at a temperature of 773 K and pressure difference of 400 kPa. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.