Platinum Metals Review - Volume 15, Issue 1, 1971

The soybean, a major crop in the United States as well as in China and Brazil, yields an oil used widely in the manufacture of margarines, salad oils, shortening, and other food products. Before use, however, it must be upgraded by selective hydrogenation of linolenates to linoleates. This paper describes research on platinum complexes that have been found to be highly selective in this reaction. The work was carried out under contract with the U.S. Department of Agriculture and was supervised by the Northern Utilisation Research and Development Division of the Agricultural Research Service.

Honeycat catalyst systems have been successfully evaluated and used in a wide range of industrial processes that emit organic fumes and odours. These include wire enamelling, paint baking, phthalic anhydride manufacture, paper coating, and nitric acid manufacture. More recently the system has been successfully evaluated for the removal of odours from the animal, fish and food processing industries.

The reactions between platinum and the refractory materials in contact with it, described in earlier articles in this series, account for many of the thermocouple failures that occur under practical industrial conditions. Reducing atmospheres accentuate such tendencies, although several factors usually cooperate to cause complete failure. This article examines the way in which platinum:rhodium-platinum thermocouples behave in service under both oxidising and reducing conditions and also in vacuum furnaces.

The high diffusibility of hydrogen in solid phases of the palladium-hydrogen system allows thermodynamic equilibrium to be established over a wide range of experimental conditions. Evidence has long existed that, in the hydride phases formed, the hydrogen:palladium ratio is not simple and is a function of equilibrium pressure and of temperature. Theoretical models of the system have often centred on modifications of the palladium electron band structure due to hydrogen absorption but increasing attention has been paid to the consequences of lattice strain. The position is now reviewed in the light of recent work.