Crystal Orientation in Pt-Based Alloys Induced by W(CO)6: Driving Oxygen Electroreduction Catalysis.

Abstract

Integrating crystal orientation as well as structural and compositional advantages into one catalyst might be a promising strategy for high-performance Pt-based catalysts for proton-exchange membrane fuel cells. Herein, by introducing W(CO)6 as a structure-oriented template, Pt-based alloys with a well-defined crystal orientation along the (111) facet were obtained. The oxygen reduction reaction mass and specific activities of the crystal-facet-tuned alloys reach a new level. Moreover, the outstanding durability stems from the combination of their exposed crystal facets and incorporated W. The density functional theory calculation results reveal that the formation of the preferred (111) alloys can be attributed to the lower free energy of (111) facets and the weaker adsorption of CO released by W(CO)6. This proposed synthesis strategy of using transition-metal carbonyl compounds as additives to synthesize alloys with strong crystal orientation may open a door to the design of various alloy catalysts with ultrahigh activity.