Pt Alloy and Intermetallic Phases with V, Cr, Mn, Ni, and Cu: Synthesis As Nanomaterials and Possible Applications As Fuel Cell Catalysts

摘要

Nanomaterials as catalysts for fuel cells are not only highly desirable, but necessary to reach the high reaction rates (or power densities) demanded by many applications. The exploration of catalyst materials beyond Pt metal, such as Pt containing alloys and intermetallics, immediately leads to significant synthetic challenges to prepare nanoparticles with controlled composition, structure, and morphology. To facilitate a comprehensive study of these materials, a generalized synthetic approach is desirable. This requires an in-depth understanding and control of relevant factors that thermo-dynamically and kinetically define the synthesis process. Once synthesized, electrochemical activities of these materials can then be studied to aid in designing the next steps in further optimizing the catalyst activity. In this work, we have been able to demonstrate synthesis of several phases (both alloy and ordered intermetallics for binary Pt-V/Mn/Cr/Ni/Cu systems) that rarely, if ever, have been synthesized as nanomaterials without using surfactants. Additionally, we have shown that some of these materials are active catalysts, with activity superior to Pt for formic acid oxidation. Finally, we have established general guidelines and methodologies for synthesis of alloy and intermetallic phases as nanomaterials with highly reactive metals like Cr, V, and Mn.