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.