High sulfur tolerance dual-functional cermet hydrogen separation membranes

There has been an urgent need for new hydrogen separation membrane materials at an acceptable cost that can operate under demanding environmental conditions while providing the desired performance. The proposed method promises to substantially decrease the material cost while maximizing the hydrogen permeation rates while meeting strong resistance to hydrogen embrittlement, not to mention that the enhancement of mechanical strength by using cermet. Most importantly, they clearly further enhance the sulfur tolerance by using not only more H2S tolerant alloys but also higher oxygen ion conducting ceramics as matrix. Our results shows that no sharp drop in hydrogen permeation flux was observed at 220 ppm H2S, which greatly exceeds the theoretical values, a 40 ppm H2S with10% H2/balance He at 600 °C, confirming that the permeated oxygen from the water splitting should have oxidized the sulfur to prevent any palladium sulfide (Pd4S) formation on the Pd-cermet membrane surface.

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► The cost-effective, optimum hydrogen permeable cermet membrane was suggested.
► Simultaneous diffusion of oxygen and hydrogen was confirmed.
► High sulfur tolerance was proved.