| 摘要 |
Skeleton catalyst electrodes are formed by vapour depositing the components of an alloy on to an electrically conducting base such as graphite and then dissolving the less noble component of the alloy layer in an acid or alkali to leave the catalytically active metal in a porous form. The catalysts include the "Reney" (Registered Trade Mark) alloys in which the active metal component may be Ni, Co, Fe, Ag, Pt, Rh, Ir, Ru, Pd and the less noble component which is dissolved out of the alloy may be Al, Sn or Zn. The alloy may also include Au, V, Mo or Cr to increase the activity of the catalyst. Suitable substrates are graphite discs, fabric or felt, sintered metal, wire mesh and metallized ceramics, plastics, fabrics or felts. The alloying components are vapour deposited, under vacuum, from separate sources either simultaneously or successively. If deposited successively, the coated substrate is heated in an inert gas or under vacuum to allow alloying of the components. The base is also heated to e.g. 300 DEG C. prior to the coating process and in one example the evaporation is effected by electron beam. Electrodes may also be made by vapour depositing the alloy components on powdered material and then condensing a plastic or metal powder on to the powder. |
