State Key Laboratory of Chemical Resource Engineering, Beijing Key Laboratory of Electrochemical Process and Technology for Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, P. R. China.
Adv Mater. 2023 Feb;35(6):e2207995. doi: 10.1002/adma.202207995. Epub 2022 Dec 18.
Structurally ordered L1 -iron triad (Fe, Co, Ni)/Pt with a M(iron triad)/Pt ratio ≈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 -M(iron triad)Pt generally requires the accurate content control of the multicomponent and the sufficient thermal energy to overcome the kinetic barrier for atom diffusion. This work reports a synthesis of sub ≈5 nm L1 -intermetallic nanoparticles using phosphide intermediate-induced structural phase transition. Taking the L1 -CoPt intermetallic, for example, the formation of the L1 structure depends on the Co 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 -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 states to improve their electrocatalytic performance. Additionally, the other L1 -M(iron triad)Pt intermetallics, i.e., L1 -NiPt and L1 -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.
具有 M(铁三角)/Pt 比≈1:1 的结构有序 L1-铁三角(Fe、Co、Ni)/Pt 在氧还原反应(ORR)电催化和燃料电池技术中引起了越来越多的关注，因为它们的强表面应变带来了高性能。然而，金属间 L1-M(铁三角)Pt 的合成通常需要多组分的精确含量控制和足够的热能来克服原子扩散的动力学障碍。本工作报道了一种使用磷化物中间相诱导结构相转变来合成亚≈5nm L1-金属间纳米粒子的方法。以 L1-CoPt 金属间化合物为例，L1 结构的形成取决于 Co P 中间相可以提供丰富的 P 空位，从而加速 Pt 扩散进入正交富 Co 骨架，而不是传统的固溶体金属间化合物途径。通过这种方法制备的 L1-CoPt 具有高度有序性，并表现出对不同负载和状态的各种 Pt 基电催化剂的广泛适应性，以提高其电催化性能。此外，还通过这种磷化物诱导的相转变制备了其他 L1-M(铁三角)Pt 金属间化合物，即 L1-NiPt 和 L1-FePt。这些发现为使用第二相诱导的结构相变设计其他金属间材料合金材料提供了有前途的策略。
