| 摘要 |
1,147,742. Gas diffusion electrode for electrolysis; sintered electrodes. SIEMENS - SCHUCKERTWERKE A. G. and VARTA A. G. April 4, 1966 [April 9, 1965], No.14879/66. Headings C7B and C7D. A gas-diffusion electrode for the electrochemical dissolution or separation of gases, e.g. the separation of H 2 , O 2 or halogens, comprises a porous working layer 7 incorporating a metal, a porous electrically insulating intermediate layer 6, and a porous metallic layer 5 which contacts the electrolyte, each layer being porous over its entire area and the layers 7 and 5 extending over the whole of the intermediate layer 6, the pores in the intermediate layer being smaller than those in the working layer and peripheral edge retaining means 3 for retaining the layers in close contact with one another. The working layer 7 may contain Ni, Pd, Pt, Ag or Ni + Ag. The intermediate layer 6 may be of asbestos Al 2 O 3 , MgO, BaSO 4 or synthetic resin. The contact layer 5 may have a potential different from that of the working layer 7 imparted to it. The layers 5 and 7 may be sieves. In an example of making a gas-diffusion electrode 8 grams of a mixture of carbonyl Ni powder (grain diameter 5Á) and KCl powder (grain diameter 200Á) as pore-former in the weight ratio 3:1 were charged into a 40mm diameter mould, an asbestos membrane was placed on the mixture, and a further 8 grams of the same pulverulent material were introduced into the mould. The three layers were pressed at 400‹ C. under a load of 9 tons. The electrode thus formed was then provided with an edging. In making electrodes including A1 2 O 3 or MgO, the oxides may be flame sprayed. |
