Abstract: There is disclosed a method for the convenient storage of material, especially noxious or radioactive material, which method comprises entrapping the material within a solid by bombarding the solid with ions of the material so as to form a concentration of the material within the solid.Forms of apparatus for carrying out this method are also described.

Abstract: In catalytic gas phase reactions there is used a catalyst comprising a sputtered deposit of catalytic material equivalent to between 0.5 and 5 monatomic layers upon a hard, substantially non-porous substrate. The substrate being hard and non-porous is of low surface area, that is not greater than 20 square meters per gram, and preferably comprises particles having a size in the range 0.1 micron to 0.5 centimeters.

Abstract: An apparatus for purifying exhaust waste gases including a catalytic element comprising a substrate of metal carrying a surface layer compatible with and supporting a coating of catalytic material, a major proportion of the surface coating of catalytic material comprising an unagglomerated atomic dispersion. An example of such a substrate is an aluminum bearing ferritic steel which has been heat treated in air to form an essentially alumina surface layer.

Abstract: A catalyst suitable, for example, for treatment of cat exhaust emissions is prepared by providing a substrate with a continuous adherent, surface layer of a carrier material for catalytic material by providing on the substrate a layer of carrier material, at least part of which comprises a gel, and firing; and sputtering catalytic material onto the surface layer by bombarding a source of the catalytic material in the neighbourhood of the surface layer with energetic ions, the conditions of atmosphere and selectivity of ions permitted to bombard the catalytic material being such that co-deposition upon the surface layer of unwanted material is avoided.