TY - JOUR
AU - Weckhuysen, Bert M.
AB - Typical industrial olefin polymerization processes to
produce both
commodity and specialty polyolefin grades are mainly based on spherical,
heterogeneous catalyst particles. During α-polymerization, heat
from the exothermic reaction and pressure induced by the growing polymer
chains on the catalyst particle lead to fragmentation, revealing active
sites for further polymerization. To study these phenomena precisely
and in-depth, we utilized a Nd-doped LaOCl-supported metallocene model
system. This model catalyst can accurately display fluctuations in
temperature with luminescence thermometry. During mild gas phase prepolymerization
conditions, we observed a temperature difference of +43 °C and
link this to the exothermicity of the ethylene polymerization reaction.
In addition, the fragmentation behavior of the model catalyst was
accurately monitored. The shell feature of the catalyst ruptured layer-by-layer,
while the inner core fragmented via a bisectional fragmentation mechanism.
We demonstrated that it is possible to probe the individual temperatures
of multiple catalyst support particles within the field-of-view of
the probe. This was correlated to structural changes and kinetics
in an α-olefin polymerization catalyst. This powerful toolbox
could be applied to different heterogeneous catalytic systems to correlate
the temperature profile with morphological evolution.
TI - In-Situ ThermometryReveals Fragmentation BehaviorBased on Local Temperature in α-Olefin PolymerizationCatalysts
JF - Journal of the American Chemical Society
DO - 10.1021/jacs.4c11357
DA - 2025-02-10
UR - https://www.deepdyve.com/lp/pubmed-central/in-situ-thermometryreveals-fragmentation-behaviorbased-on-local-4EX9VApOvj
SP - 5642
EP - 5648
VL - 147
IS - 7
DP - DeepDyve
ER -