Synthesis, shape control, and methanol electro-oxidation properties of Pt-Zn alloy and Pt 3Zn intermetallic nanocrystals

Abstract

Figure Persented: We report the first synthesis of highly monodisperse Pt 3Zn nanocrystals (NCs). Shape-controlled synthesis generates cubic and spherical Pt-Zn NCs. Reaction temperature is the key to incorporate Zn into Pt, even in the absence of a strong reducing agent. The Pt-Zn NCs are active toward methanol oxidation, with the spherical NCs exhibiting higher activity than the cubic NCs. The Pt-Zn alloy phase can be transformed into the Pt 3Zn intermetallic phase, upon annealing. The intermetallic Pt 3Zn shows better performance than the alloy phase Pt-Zn. Besides the activity toward methanol oxidation, Pt-Zn NCs show excellent poisoning tolerance. With activities comparable to the commercial Pt catalyst, enhanced poisoning tolerance and lower cost, Pt-Zn and Pt 3Zn NCs are a promising new family of catalysts for direct methanol fuel cells. © 2012 American Chemical Society.