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

Pure Pd membranes could be used for H-2 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 H-2 flux and N-2 leak rate (J(N2)) remained stable during 200 h continuous operation in H-2 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 H-2 permeability, rendering them promising candidates for processes that require H-2 separation at ambient temperatures. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.