ROLE OF RARE EARTHS IN CATALYSIS, THE - VOL.29

Chapters devoted primarily to catalysis have been published in earlier volumes of the Handbook. In this volume several more are added. The first is an extension of the earlier chapter 43, on interactions at surfaces of metals and alloys, to reactions such as hydrogenation, methanation, ammonia synthesis, saturated hydrocarbon reactions, dehydrogenation of hydrogenated materials, hydrodesulfurization, and carbon monoxide oxidation. The second chapter reports on the wide variety of catalyzed reactions involving metals and alloys in the innovated form of metal overlayers or bimetallic compounds with some transition metals produced from ammonia solutions. This is followed by a chapter on catalysis with mixed oxides usually having perovskite or perovskite-related structures. Then follows a comprehensive discussion on the background and current role of cerium oxide and associated materials for post-treatment of exhaust gases for pollution control. These three-way catalysts (TWC) are designed to render harmless the CO, NOx, and unburned hydrocarbons from internal combustion engines. The next chapter considers the wide field of zeolite catalysts containing rare earths from their historic use in petroleum refining in the 1960s to other petrochemical and fine chemical applications today. The final chapter documents the use of the triflates (the trifluoro-methane-sulfonyl group which is a hard Lewis acid in both aqueous and organic solutions) as versatile catalysts in carbon-carbon bond-forming reactions. Their stability in the presence of water, in spite of their being hard Lewis acids, enhances their growing usefulness.