Hydrogen permeabilities were measured for a series of fcc Pd-Au alloy membranes at 393 to 573K (table 142). The maximum permeability was found at an atom fraction of XAu = 0.11; which agreed closely with a theoretically predicted value. For a series of Pd-Au alloy membranes with various Au contents, diffusion constants, activation energies and pre-exponential factors were determined as a function of H content. Hydrogen concentration-independent values of these parameters were obtained by extrapolation to H → 0, where the H solution behaved ideally.

Hydrogen Permeation through FCC Pd-Au Alloy Membranes. T.B.Flanagan, D.Wang: Journal of Physical Chemistry C, 2011, 115[23], 11618-23

 

Table 143

Diffusion of H in Pd Alloys

 

Solute

C (at%)

Do (m2/s)

E (kJ/mol)

-

0

1.05 x 10-7

21.42

B

2.5

1.03 x 10-7

20.88

B

5.0

8.33 x 10-8

20.47

B

7.5

5.40 x 10-8

19.86

B

10.0

3.30 x 10-8

18.77

Ce

2.0

3.46 x 10-8

18.07

Ce

4.0

2.21 x 10-8

16.57

Ce

6.0

1.75 x 10-8

15.90

Ce

8.0

1.89 x 10-8

15.86

Ce

10.0

2.19 x 10-8

16.32

Y

2.0

1.08 x 10-7

21.17

Y

3.9

9.66 x 10-8

20.79

Y

6.0

7.99 x 10-8

20.33

Y

8.0

4.49 x 10-8

19.20

Y

10.0

1.90 x 10-8

17.53