Long-term hydrogen permeation tests of Pd-Cu-Ni/PNS with temperature cycles from room temperature to 773 K

Pd-Cu-Ni ternary alloy membranes were fabricated on a porous nickel support by sputtering followed by the Cu-reflow method. The weight composition of Pd:Cu:Ni was 88.9:7.4:3.7 and the thickness was 12 μm. α-β phase transition tests were carried out using hydrogen gas in the temperature range from 373 to 623 K using feed side pressures of 0.052 and 0.138 MPa. There were neither peaks nor shoulders in the hydrogen flux across the entire temperature range, meaning that the α-β phase transition did not occur below the critical points of the Pd-H system, i.e. 565 K, 1.97 MPa. The durability of the membranes was demonstrated by performing temperature cycles from room temperature to 773 K at a feed side pressure of 0.138 MPa and this was attributed to the phase stability of the α-phase even at room temperature.