碳热震法合成高熵合金纳米颗粒。

Carbothermal shock synthesis of high-entropy-alloy nanoparticles.

机构信息

Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA.

Department of Mechanical and Industrial Engineering, University of Illinois at Chicago (UIC), Chicago, IL 60607, USA.

出版信息

Science. 2018 Mar 30;359(6383):1489-1494. doi: 10.1126/science.aan5412.

DOI:10.1126/science.aan5412

PMID:29599236

Abstract

The controllable incorporation of multiple immiscible elements into a single nanoparticle merits untold scientific and technological potential, yet remains a challenge using conventional synthetic techniques. We present a general route for alloying up to eight dissimilar elements into single-phase solid-solution nanoparticles, referred to as high-entropy-alloy nanoparticles (HEA-NPs), by thermally shocking precursor metal salt mixtures loaded onto carbon supports [temperature ~2000 kelvin (K), 55-millisecond duration, rate of ~10 K per second]. We synthesized a wide range of multicomponent nanoparticles with a desired chemistry (composition), size, and phase (solid solution, phase-separated) by controlling the carbothermal shock (CTS) parameters (substrate, temperature, shock duration, and heating/cooling rate). To prove utility, we synthesized quinary HEA-NPs as ammonia oxidation catalysts with ~100% conversion and >99% nitrogen oxide selectivity over prolonged operations.

摘要

可控地将多种不混溶的元素并入单个纳米粒子中具有巨大的科学和技术潜力，但使用传统的合成技术仍然是一个挑战。我们提出了一种通用的方法，通过热冲击负载在碳载体上的前驱体金属盐混合物，可以将多达八种不同的元素合金化形成单相固溶体纳米粒子，称为高熵合金纳米粒子（HEA-NPs）[温度约 2000 开尔文（K），55 毫秒持续时间，约每秒 10 K 的升温速率]。我们通过控制碳热冲击（CTS）参数（基底、温度、冲击持续时间和加热/冷却速率），以控制所需化学组成、尺寸和相（固溶体、相分离）来合成多种成分的纳米粒子。为了证明其效用，我们合成了五元高熵合金纳米粒子作为氨氧化催化剂，在长时间操作中具有~100%的转化率和>99%的氮氧化物选择性。