Sulfur tolerant PdAu and PdAuPt alloy hydrogen separation membranes

Advanced Palladium Membrane Scale-up for Hydrogen Separation

“…The membrane was observed to have 93% of the H 2 permeability of a pure Pd foil at the same thickness while the previous Pd-Cu membranes gave about 50-60 % of the permeability compared to pure Pd foils [12]. Pd-Au membranes were also tested for sulfur resistance [13,14]. It was also shown by McKinley [8] that a 5 wt.% Au -95 wt.% Pd alloy membranes showed good H 2 permeability.…”

“…A Pd-Au alloy membrane with 8 wt.% Au showed resistance to bulk sulfidation upon exposure to a 54.8 ppmv H 2 S-H 2 mixture in the temperature range of 350 °C -500 °C but a H 2 permeance decline was also observed [13]. A 33-µm, 80 wt.% Pd -10 wt.% Au -10 wt.% platinum (Pt) membrane was evaluated with syngas and a H 2 permeance decline of approximately 21 % H 2 flux decline was observed once 20 ppmv H 2 S was added into the feed [14].…”

Pd-Alloy membranes for hydrogen separation

“…This is a notable result because the PdRu binary is less permeable than pure Pd [54]. Coulter reported a Pd 88 Au 6 Pt 6 with permeability that is 76% of pure Pd at 400 C [44]. Braun observed that a Pd 83 Ag 2 Au 15 alloy was slightly more permeable than Pd at 400 C [21].…”

“…In general, minor component atoms that are 'large' relative to Pd increase Pd's FCC lattice parameter, which, in turn, leads to both greater H-atom solubility and more-facile H-atom diffusion [8]. Figure 4 shows how permeability (relative to pure Pd near 400 C, minor component <$10 at.%) varies with the metallic radius of the minor component [8,[44][45][46]. Minor components with radii smaller than Pd's, such as Cu, Ru, and Ni, reduce Pd's permeability (lower left shaded area).…”

Influence of Hydrogen Sulfide and Redox Reactions on the Surface Properties and Hydrogen Permeability of Pd Membranes

“…Though the sulfides could be desorbed using zinc oxide powder or high-temperature sulphur adsorbent [12,13], great damage was caused to the Pd membrane used in highly-pure hydrogen preparation [14]. Based on the development trend of the Pd membrane with sulfuration resistance, high hydrogen permeation and low cost [15][16][17][18][19][20][21][22], the study of the influence mechanisms of sulfides on the Pd membrane surface was necessary. Some valuable was necessary.…”