INTERMETALLIC COMPOUNDS AS MODELS FOR MATERIALS FORMED AT THE METAL CRYSTALLITE-OXIDE SUPPORT INTERFACE.

Evidence from the literature suggests that intermetallic compounds may form from the interaction of small metal crystallites with supposedly inert oxide supports (for example, PtTi//X from Pt on TiO//2 or NiSi//y from Ni on SiO//2). In order to characterize these materials more fully, the authors have undertaken a program to study both compounds. Fundamental experiments on single crystalline substrates under UHV conditions reveal that these materials have unique chemisorption properties which can be exploited to yield both highly selective and highly active catalysts. The authors have also demonstrated that similar materials may be grown by reacting volatile main group organometallic compounds (such as alkylsilanes) with clean metal substrates. It is shown high surface area, supported intermetallic compound and alloy catalysts can be made readily. (Author abstract. )