Open AccessExperiments on heavy hydrogen IV—The hydrogenation and exchange reaction of ethylene with heavy hydrogen
Author(s) -
A. Farkas,
L. Farkas,
Eric K. Rideal
Publication year - 1934
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1934.0177
Subject(s) - catalysis , hydrogen , ethylene , chemistry , vapours , nickel , metal , inorganic chemistry , platinum , molecule , adsorption , carbon monoxide , photochemistry , organic chemistry , neuroscience , biology
Hitherto it has generally been assumed that the catalytic hydrogenation of ethylene linkages in organic compounds at surfaces such as nickel or platinum involves merely the direct addition of a molecule of hydrogen across the double bond. In view of the fact that chemi-adsorbed hydrogen on catalytically active metallic substrates is in the atomic form it seemed possible that the reaction was indeed a more involved one than that suggested by the simple hypothesis referred to. By employing mixtures of light and heavy hydrogen it is possible to follow the reaction in more detail since the fate of the "labelled" heavy hydrogen atoms can be determined. Ethylene itself was used as a suitable substance for examination since it is readily hydrogenated at relatively low temperatures and complications due to other reactions are under these conditions absent.Experimental The experimental arrangement was very simple and is shown in fig. 1. The catalyst employed was in the form of a nickel wire, 0·1 mm diameter and 15 cm long, which was "activated" by oxidation, at 600ºC, and reduction, at 300ºC, several times in succession. The temperature of the wire was controlled by measuring its resistance in a Wheatstone-bridge. The trap D which was cooled by acetone carbon dioxide mixture served to protect the catalyst from poisoning by tap grease or by mercury vapours.