| abstract |
A filter for purifying hydrogen which has a porous support and a Pd alloy film being bond onto one surface of the support, wherein the porous support has such pores that a thickness (T) of the porous support, a diameter (D1) of the opening of a pore at the Pd alloy film bonded side and a diameter (D2) of the opening of the opposite side of the pore satisfy the relationships: 1.0 ≤ D1/T ≤ 5.0 and 1.0 ≤ D2/T ≤ 5.0, a diameter (D1) of the opening of a pore at the Pd alloy film bonded side, a diameter (D2) of the opening of the opposite side of the pore and a diameter (D3) of the opening of the narrowest portion of the pore satisfy the relationships: D3/D1 < 0.8 and D3/D2 < 0.9 and D3 < 250 μm, and further the total area of the openings of the pores at the Pd alloy film bonded side accounts for 20 to 80 % of the area of the porous support. |