The electrical condition of hot surfaces during the adsorption of gases. Part I.-Gold and silver surfaces at temperatures up to 850°C

Abstract

In 1914, Dr. H. Hartley published an account of an investigation upon the electrical condition of a gold surface heated in contact with various gases, in the course of which he found, inter alia , that gold acquired a negative charge when in contact with hydrogen or carbonic oxide, or a mixture of either of these gases with oxygen, and a positive charge when in contact with oxygen alone. In view of the fact that these interesting and significant results indicate a possible clue to the mechanism and nature of the heterogeneous catalysis of gaseous reactions by hot surfaces, the present investigation was undertaken with the object of confirming and extending Dr. Hartley’s work. The main difficulty encountered in the course of this investigation lay in the avoiding of spurious electrical effects. We believe, however, that the design and arrangement of apparatus finally adopted by us were such as to preclude the occurrence of such effects. It was also found necessary to employ a pumping system which would permit of the rapid attainment of a high degree of vacuum, and to prevent ingress of any traces of mercury vapour into the vessel containing the metal surface, which would otherwise have been contaminated with mercury.