A novel mechanism for metal alloying at the nanoscale
Name
1051458861-MIT.pdf
Description
Full printable version
Size
5.84 MB
Format
Adobe PDF
Checksum (MD5)
d1f638a2baf4cfe9df720cf99fd67a8b
Author(s)
Yu, Daiwei
Advisor(s)
Ju Li.
Date Issued
2018
Publisher
Massachusetts Institute of Technology
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 propose a novel mechanism for metal alloying at the nanoscale, which provides a general route for alloying dissimilar elements into single-phase solid-solution nanoparticles, referred to as high-entropy-alloy nanoparticles (HEA-NPs). To validate the theory, we developed a facile carbothermal shock (CTS) method to synthesize a wide range of multicomponent (up to eight dissimilar elements) nanoparticles with a desired chemistry (composition), size, and phase (solid solution, phase-separated) by controlling the 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. This mechanism is distinct from previously reported alloying processes, which can bring about a new repertoire of alloys and nanostructures with unprecedented functionalities.
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 39-40).
Subjects
Electrical Engineering and Computer Science.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
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