Atomic-Scale Mechanism on Nucleation and Growth of Mo2C Nanoparticles Revealed by in Situ Transmission Electron Microscopy

Linfeng Fei, Sheung Mei Ng, Wei Lu, Ming Xu, Longlong Shu, Wei Bing Zhang, Zehui Yong, Tieyu Sun, Chi Hang Lam, Chi Wah Leung, Chee Leung Mak, Yu Wang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

17 Citations (Scopus)

Abstract

With a similar electronic structure as that of platinum, molybdenum carbide (Mo2C) holds significant potential as a high performance catalyst across many chemical reactions. Empirically, the precise control of particle size, shape, and surface nature during synthesis largely determines the catalytic performance of nanoparticles, giving rise to the need of clarifying the underlying growth characteristics in the nucleation and growth of Mo2C. However, the high-temperature annealing involved during the growth of carbides makes it difficult to directly observe and understand the nucleation and growth processes. Here, we report on the use of advanced in situ transmission electron microscopy with atomic resolution to reveal a three-stage mechanism during the growth of Mo2C nanoparticles over a wide temperature range: initial nucleation via a mechanism consistent with spinodal decomposition, subsequent particle coalescence and monomer attachment, and final surface faceting to well-defined particles with minimum surface energy. These microscopic observations made under a heating atmosphere offer new perspectives toward the design of carbide-based catalysts, as well as the tuning of their catalytic performances.
Original languageEnglish
Pages (from-to)7875-7881
Number of pages7
JournalNano Letters
Volume16
Issue number12
DOIs
Publication statusPublished - 14 Dec 2016

Keywords

  • crystal growth
  • in situ heating
  • molybdenum carbide
  • nanoparticles
  • nucleation
  • Transmission electron microscopy

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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