A Study of the Catalysis by Nickel of the Union of Hydrogen and Oxygen by a New Method

D. L. Chapman, J. E. Ramsbottom and C. G. Trotman have shown that silver which has been heated to dull redness in oxygen is distinctly inferior as a catalyst for the reaction between hydrogen and oxygen to silver from which all the dissolved oxygen has been removed. To explain this fact they advanced the working hypothesis that silver which contains more than a given concentration of dissolved oxygen is covered on its surface with an oxide which is not reduced under the conditions which obtain during the process of catalysis. In order to test the theory the catalytic activity of a comparatively easily oxidized metal, namely nickel, has been investigated. The investigation has led us to the discovery of a simple and delicate method of testing whether a metallic surface is covered with a layer of oxide. This method depends on the fact that a hot metal imparts less energy to a gas molecule (especially a hydrogen molecule) reflected from its surface than that communicated to the molecule under corresponding conditions by the oxide of the metal. It is our intention to apply the test to a silver surface in the oxidized and in the reduced state.