Synthesis of L1 0 -Iron Triad (Fe, Co, Ni)/pt Intermetallic Electrocatalysts Via a Phosphide-Induced Structural Phase Transition.

Structurally ordered L1 0 -iron triad (Fe, Co, Ni)/Pt with a M(iron triad)/Pt ratio around 1:1 has drawn increasing attention in oxygen reduction reaction (ORR) electrocatalysis and fuel cell technologies by virtue of the high performance derived from their strong surface strain. However, the synthesis of intermetallic L1 0 -M(iron triad)Pt generally requires the accurate content control of multicomponent and the sufficient thermal energy to overcome the kinetic barrier for atom diffusion. This work reports a synthesis of sub ∼5 nm L1 0 -intermetallic nanoparticles using phosphide intermediates induced structural phase transition. Taking the L1 0 -CoPt intermetallic for examples, the formation of the L1 0 structure depends on the Co 2 P intermediates can provide abundant P vacancies to accelerate the Pt diffusion into the orthorhombic Co-rich skeletons, instead of the traditional route of intermetallic from solid solution. L1 0 -CoPt prepared by this method has a high degree of ordering, and shows the broad adaptability of various Pt-based electrocatalysts with different loading and state to improve their electrocatalytic performance. Additionally, the other L1 0 -M(iron triad)Pt intermetallics, i.e., L1 0 -NiPt and L1 0 -FePt, are also prepared through this phosphide-induced phase transition. The findings provide a promising strategy for designing other intermetallic materials alloy materials using a structural phase transition induced by a second phase. This article is protected by copyright. All rights reserved.