Isolating
Clusters of Light Elements in Molecular
Sieves with Atom Probe Tomography
Version 2 2018-07-13, 16:55
Version 1 2018-07-12, 23:30
Posted on 2018-07-13 - 16:55
Understanding the
3-D distribution and nature of active sites in
heterogeneous catalysts is critical to developing structure–function
relationships. However, this is difficult to achieve in microporous
materials as there is little relative z-contrast between active and
inactive framework elements (e.g., Al, O, P, and Si), making them
difficult to differentiate with electron microscopies. We have applied
atom probe tomography (APT), currently the only nanometer-scale 3-D
microscopy to offer routine light element contrast, to the methanol-to-hydrocarbons
(MTH) catalyst SAPO-34, with Si as the active site, which may be present
in the framework as either isolated Si species or clusters (islands)
of Si atoms. 29Si solid-state NMR data on isotopically
enriched and natural abundance materials are consistent with the presence
of Si islands, and the APT results have been complemented with simulations
to show the smallest detectable cluster size as a function of instrument
spatial resolution and detector efficiency. We have identified significant
Si–Si affinity in the materials, as well as clustering of coke
deposited by the MTH reaction (13CH3OH used)
and an affinity between Brønsted acid sites and coke. A comparison
with simulations shows that the ultimate spatial resolution that can
be attained by APT applied to molecular sieves is 0.5–1 nm.
Finally, the observed 13C clusters are consistent with
hydrocarbon pool mechanism intermediates that are preferentially located
in regions of increased Brønsted acidity.
CITE THIS COLLECTION
DataCite
3 Biotech
3D Printing in Medicine
3D Research
3D-Printed Materials and Systems
4OR
AAPG Bulletin
AAPS Open
AAPS PharmSciTech
Abhandlungen aus dem Mathematischen Seminar der Universität Hamburg
ABI Technik (German)
Academic Medicine
Academic Pediatrics
Academic Psychiatry
Academic Questions
Academy of Management Discoveries
Academy of Management Journal
Academy of Management Learning and Education
Academy of Management Perspectives
Academy of Management Proceedings
Academy of Management Review
Schmidt, Joel E.; Peng, Linqing; Paioni, Alessandra Lucini; Ehren, Helena Leona; Guo, Wei; Mazumder, Baishakhi; et al. (2018). Isolating
Clusters of Light Elements in Molecular
Sieves with Atom Probe Tomography. ACS Publications. Collection. https://doi.org/10.1021/jacs.8b04494
or
Select your citation style and then place your mouse over the citation text to select it.
SHARE
Usage metrics
Read the peer-reviewed publication
AUTHORS (14)
JS
Joel E. Schmidt
LP
Linqing Peng
AP
Alessandra Lucini Paioni
HE
Helena Leona Ehren
WG
Wei Guo
BM
Baishakhi Mazumder
DA
D. A. Matthijs de Winter
OA
Özgün Attila
DF
Donglong Fu
AC
Abhishek Dutta Chowdhury
KH
Klaartje Houben
MB
Marc Baldus
JP
Jonathan D. Poplawsky
BW
Bert M. Weckhuysen
KEYWORDS
13 C clustersSi specieslight element contrastelectron microscopiesMTH reactionatom probe tomographyBr ønsted aciditySi islandsAtom Probe TomographyNMR dataabundance materialsSAPOmicroporous materialsdetector efficiencycluster size29 SiAPT resultsframework elements13 CH 3 OHhydrocarbon pool mechanism intermediatesSi atomsnanometer-scale 3- D microscopy3- D distributionBr ønsted acid sitesMolecular SievesLight Elements