Interstitial boron atoms in palladium lattice of industrial type of nano-catalyst: Properties and structural modifications

DOI: 10.1021/jacs.9b06120

Authors: Tianyi Chen (University of Oxford) , Ieuan Ellis (University of Oxford; Johnson Matthey) , Thomas Hooper (University of Warwick) , Emanuela Liberti (University of Oxford) , Lin Ye (University of Oxford) , Tsz Woon Benedict Lo (University of Oxford) , Colum O'Leary (University of Oxford) , Alexandra A. Sheader (University of Oxford) , Gerardo T. Martinez (University of Oxford) , Lewys Jones (University of Oxford) , Ping-Luen Ho (University of Oxford) , Pu Zhao (University of Oxford) , James Cookson (Johnson Matthey) , Peter T Bishop (Johnson Matthey) , Philip A. Chater (Diamond Light Source) , John V. Hanna (University of Warwick) , Peter D. Nellist (University of Oxford) , Shik Chi Edman Tsang (University of Oxford)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Journal Of The American Chemical Society

State: Published (Approved)
Published: November 2019
Diamond Proposal Number(s): 15452

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 implies 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 enables the characterization of industrial metal nanocatalysts across length scales from macro-analysis to micro-analysis, which gives important guidance to structure-activity relationship of the system.

Journal Keywords: Nanomaterial; electron microscopy; crystal structure

Subject Areas: Chemistry, Materials


Instruments: I11-High Resolution Powder Diffraction , I15-1-X-ray Pair Distribution Function (XPDF)

Added On: 25/11/2019 11:03

Discipline Tags:

Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Diffraction Scattering X-ray Powder Diffraction Pair Distribution Function (PDF)