Interstitial boron atoms in the palladium lattice of an industrial type of nanocatalyst: Properties and structural modifications

Tianyi Chen, Ieuan Ellis, Thomas J.N. Hooper, Emanuela Liberti, Lin Ye, Benedict T.W. Lo, Colum O’Leary, Alexandra A. Sheader, Gerardo T. Martinez, Lewys Jones, Ping Luen Ho, Pu Zhao, James Cookson, Peter T. Bishop, Philip Chater, John V. Hanna, Peter Nellist, Shik Chi Edman Tsang (Corresponding Author)

Research output: Journal article publicationJournal articleAcademic researchpeer-review

11 Citations (Scopus)

Abstract

It is well-established that the inclusion of small atomic species such as boron (B) in powder metal catalysts can subtly modify catalytic properties, and the associated changes in the metal lattice imply that the B atoms are located in the interstitial sites. However, there is no compelling evidence for the occurrence of interstitial B atoms, and there is a concomitant lack of detailed structural information describing the nature of this occupancy and its effects on the metal host. In this work, we use an innovative combination of high-resolution 11B magic-angle-spinning (MAS) and 105Pd static solid-state NMR nuclear magnetic resonance (NMR), synchrotron X-ray diffraction (SXRD), in situ X-ray pair distribution function (XPDF), scanning transmission electron microscopy-annular dark field imaging (STEM-ADF), electron ptychography, and electron energy loss spectroscopy (EELS) to investigate the B atom positions, properties, and structural modifications to the palladium lattice of an industrial type interstitial boron doped palladium nanoparticle catalyst system (Pd-intB/C NPs). In this study, we report that upon B incorporation into the Pd lattice, the overall face centered cubic (FCC) lattice is maintained; however, short-range disorder is introduced. The 105Pd static solid-state NMR illustrates how different types (and levels) of structural strain and disorder are introduced in the nanoparticle history. These structural distortions can lead to the appearance of small amounts of local hexagonal close packed (HCP) structured material in localized regions. The short-range lattice tailoring of the Pd framework to accommodate interstitial B dopants in the octahedral sites of the distorted FCC structure can be imaged by electron ptychography. This study describes new toolsets that enable the characterization of industrial metal nanocatalysts across length scales from macro- to microanalysis, which gives important guidance to the structure–activity relationship of the system.

Original languageEnglish
Pages (from-to)19616-19624
Number of pages9
JournalJournal of the American Chemical Society
Volume141
Issue number50
DOIs
Publication statusPublished - 1 Jan 2020
Externally publishedYes

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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