H2 purification process with double layer bcc-PdCu alloy membrane at ambient temperature

Abstract Pure Pd membranes could be used for H2 purification only at high temperature (over 573 K) due to tendency to embrittlement when exposed to hydrogen at lower temperatures especially when approaching ambient temperature. To solve this problem, a double layer bcc-PdCu alloy membrane was prepared by alternating electrodeposition of Pd and Cu on a ceramic support membrane that allowed to be operated down to room temperature. The H2 flux and N2 leak rate (JN2) remained stable during 200 h continuous operation in H2 at 303 K. Kinetic characteristics of the supported bcc PdCu membranes were explored over a wider temperature range as well. The marginal hydrogen solubility in bcc PdCu alloys and considerable H diffusivity guaranteed the excellent low-temperature tolerance and favorable H2 permeability, rendering them promising candidates for processes that require H2 separation at ambient temperatures.