A novel mechanism for metal alloying at the nanoscale

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.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2018

Author dc:creator

• Yu, Daiwei

Advisor dc:contributor.advisor

• Ju Li.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/118032

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/118032