Shape-enhanced ammonia electro-oxidation property of a cubic platinum nanocrystal catalyst prepared by surfactant-free synthesis

Abstract

Carbon-supported cubic platinum nanocrystals (PtNC/C) with clean surfaces have been prepared using a facile, scalable, and surfactant-free method, in which impregnated Pt precursors on a C support are reduced in a mixture of hydrogen and carbon monoxide. The influence of synthesis parameters on the morphology of final products is investigated. The cubic Pt/C is studied for the catalytic property in electro-oxidation of ammonia. It exhibits a significant shape effect, with much improved activity and better durability compared to commercial Pt/C and Pt particles with other morphologies. The observed shape dependency of electrocatalytic property is attributed to changes in electronic/geometric structures and varying coverage of N_ad, a poisoning species, on different Pt surfaces.