Nanocrystalline Intermetallics and Alloys

Nanocrystalline intermetallics and alloys are novel materials with high surface areas which are potential low-cost and high-performance catalysts.Here,we report a general approach to the synthesis of a large variety of nanocrystalline intermetallics and alloys with controllable composition,size,and morphology:these include Au-,Pd-,Pt-,Ir-,Ru-,and Rh-based bi-or tri-metallic nanocrystals.We find that only those intermetallics and alloys whose effective electronegativity is larger than a critical value(1.93)can be prepared by co-reduction in our synthetic system.Our methodology provides a simple and convenient route to a variety of intermetallic and alloyed nanomaterials which are promising candidates for catalysts for reactions such as methanol oxidation,hydroformylation,the Suzuki reaction,cyclohexene hydroconversion,and the selective hydrogenation of acetylene.