A thin supported Pd-Au based membrane for hydrogen generation and purification: A case study

In this work, a composite membrane based on a thin Pd-Au metallic layer supported on a ceramic substrate was produced by electroless plating deposition with the intent of generating and, meanwhile, purifying hydrogen in a single stage.Permeation tests were performed with pure gases (H2, N2, CO2, CH4) on both of them by varying the temperature between 300 ° C and 400 ° C and the feed pressure from 150 to 250 kPa to evaluate the hydrogen perm-selectivity characteristics of the membrane.A reference H2/N2 ideal selectivity around 500 was reached at 400 ° C and 50 kPa of transmembrane pressure and it remained stable up to 600 h under operation.The presence of defects on the metallic layer affected negatively the membrane performance in terms of H2 perm-selectivity, probably caused by the absence on an intermediate layer, which did not compensate the mechanical stress due to different thermal dilation coefficients within the metallic layer and the ceramic substrate.