PMID- 34240080
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20240403
IS  - 2691-3704 (Electronic)
IS  - 2691-3704 (Linking)
VI  - 1
IP  - 6
DP  - 2021 Jun 28
TI  - Heterogeneity in the Fragmentation of Ziegler Catalyst Particles during Ethylene 
      Polymerization Quantified by X-ray Nanotomography.
PG  - 852-864
LID - 10.1021/jacsau.1c00130 [doi]
AB  - Ziegler-type catalysts are the grand old workhorse of the polyolefin industry, 
      yet their hierarchically complex nature complicates polymerization 
      activity-catalyst structure relationships. In this work, the degree of catalyst 
      framework fragmentation of a high-density polyethylene (HDPE) Ziegler-type 
      catalyst was studied using ptychography X-ray-computed nanotomography (PXCT) in 
      the early stages of ethylene polymerization under mild reaction conditions. An 
      ensemble consisting of 434 fully reconstructed ethylene prepolymerized Ziegler 
      catalyst particles prepared at a polymer yield of 3.4 g HDPE/g catalyst was 
      imaged. This enabled a statistical route to study the heterogeneity in the degree 
      of particle fragmentation and therefore local polymerization activity at an 
      achieved 3-D spatial resolution of 74 nm without requiring invasive imaging 
      tools. To study the degree of catalyst fragmentation within the ensemble, a 
      fragmentation parameter was constructed based on a k-means clustering algorithm 
      that relates the quantity of polyethylene formed to the average size of the 
      spatially resolved catalyst fragments. With this classification method, we have 
      identified particles that exhibit weak, moderate, and strong degrees of catalyst 
      fragmentation, showing that there is a strong heterogeneity in the overall 
      catalyst particle fragmentation and thus polymerization activity within the 
      entire ensemble. This hints toward local mass transfer limitations or other 
      deactivation phenomena. The methodology used here can be applied to all 
      polyolefin catalysts, including metallocene and the Phillips catalysts to gain 
      statistically relevant fundamental insights in the fragmentation behavior of an 
      ensemble of catalyst particles.
CI  - (c) 2021 The Authors. Published by American Chemical Society.
FAU - Bossers, Koen W
AU  - Bossers KW
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
FAU - Valadian, Roozbeh
AU  - Valadian R
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
FAU - Garrevoet, Jan
AU  - Garrevoet J
AD  - Photon Science at Deutsches Elektronen-Synchrotron DESY, Hamburg 22603, Germany.
FAU - van Malderen, Stijn
AU  - van Malderen S
AD  - Photon Science at Deutsches Elektronen-Synchrotron DESY, Hamburg 22603, Germany.
FAU - Chan, Robert
AU  - Chan R
AD  - SABIC, P.O. Box 319, 6160 AH Geleen, The Netherlands.
FAU - Friederichs, Nic
AU  - Friederichs N
AD  - SABIC, P.O. Box 319, 6160 AH Geleen, The Netherlands.
FAU - Severn, John
AU  - Severn J
AD  - DSM Materials Science Center, 6167 RD Geleen, The Netherlands.
FAU - Wilbers, Arnold
AU  - Wilbers A
AD  - DSM Materials Science Center, 6167 RD Geleen, The Netherlands.
FAU - Zanoni, Silvia
AU  - Zanoni S
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
FAU - Jongkind, Maarten K
AU  - Jongkind MK
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
FAU - Weckhuysen, Bert M
AU  - Weckhuysen BM
AUID- ORCID: 0000-0001-5245-1426
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
FAU - Meirer, Florian
AU  - Meirer F
AUID- ORCID: 0000-0001-5581-5790
AD  - Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, 
      Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
LA  - eng
PT  - Journal Article
DEP - 20210504
PL  - United States
TA  - JACS Au
JT  - JACS Au
JID - 101775714
PMC - PMC8243319
COIS- The authors declare no competing financial interest.
EDAT- 2021/07/10 06:00
MHDA- 2021/07/10 06:01
PMCR- 2021/05/04
CRDT- 2021/07/09 07:04
PHST- 2021/03/21 00:00 [received]
PHST- 2021/07/09 07:04 [entrez]
PHST- 2021/07/10 06:00 [pubmed]
PHST- 2021/07/10 06:01 [medline]
PHST- 2021/05/04 00:00 [pmc-release]
AID - 10.1021/jacsau.1c00130 [doi]
PST - ppublish
SO  - JACS Au. 2021 Jun 28;1(6):852-864. doi: 10.1021/jacsau.1c00130. Epub 2021 May 4.