Facet-Controlled Metal Alloy Electrocatalysts for Oxygen Reduction Reaction: Unconventional Post Treatment of Pt3Ni Octahedral Catalysts for Enhanced Activity

Recent advancement of low-temperature proton-exchange membrane (PEM) fuel cell technology can be attributed in part to the rapid development of electrocatalysts for reduction of oxygen.  Such electrocatalysts can now be prepared with very high level of precision in size, shape and composition to meet the increasingly stringent performance targets in activity and durability [1].  The new synthetic methods are based predominately on the solution phase approach where the control of reaction kinetics can be more precise than that for the impregnation method [2]. 

In this talk, I will present the recent progress on the design and synthesis of metal alloy nanostructures. I will discuss the approach to the preparation of facet-controlled Pt alloy nanoparticles based on the gas reducing agent in liquid solution (GRAILS) method [3-4] and how this method is used in the development of structurally tuneable electrocatalysts for reduction of oxygen.  A range of plutonic shapes including {111} faceted octahedron, icosahedron and twin defect-regulated morphologies can now be made (see the TEM images). I will illustrate the relationship between size, composition, structure (including surface strain) and catalytic property (activity and stability) of these bimetallic and multimetallic nanostructured catalysts for oxygen reduction reaction (ORR) and present the likely venues for the scaled-up production.

 

References:

(1)   Peng, Z. M.; Yang, H. Nano Today, 2009, 4, 143-164; Wu, J. B.; Yang, H. Acc. Chem. Res., 2013, 46, 1848-1857.

(2)   You, H. J.; Yang, S. C.; Ding, B. J.; Yang, H. Chem. Soc. Rev., 2013, 42, 2880-2904.

(3)   Wu, J. B.; Qi, L.; You, H. J.; Gross, A. Li, J. Yang, H. J. Am. Chem. Soc., 2012, 134, 11880-11883.

(4)    Wu, J. B.; Gross, A.; Yang, H. Nano Lett., 2011, 11, 798-802.