Single-Molecule
Fluorescence Microscopy Reveals Local
Diffusion Coefficients in the Pore Network of an Individual Catalyst
Particle
Frank
C. Hendriks
Florian Meirer
Alexey V. Kubarev
Zoran Ristanović
Maarten B. J. Roeffaers
Eelco T. C. Vogt
Pieter C. A. Bruijnincx
Bert M. Weckhuysen
10.1021/jacs.7b07139.s002
https://acs.figshare.com/articles/media/Single-Molecule_Fluorescence_Microscopy_Reveals_Local_Diffusion_Coefficients_in_the_Pore_Network_of_an_Individual_Catalyst_Particle/5404630
We
used single-molecule fluorescence microscopy to study self-diffusion
of a feedstock-like probe molecule with nanometer accuracy in the
macropores of a micrometer-sized, real-life fluid catalytic cracking
(FCC) particle. Movies of single fluorescent molecules allowed their
movement through the pore network to be reconstructed. The observed
tracks were classified into three different states by machine learning
and all found to be distributed homogeneously over the particle. Most
probe molecules (88%) were immobile, with the molecule most likely
being physisorbed or trapped; the remainder was either mobile (8%),
with the molecule moving inside the macropores, or showed hybrid behavior
(4%). Mobile tracks had an average diffusion coefficient of <i>D</i> = 8 × 10<sup>–14</sup> ± 1 × 10<sup>–13</sup> m<sup>2</sup> s<sup>–1</sup>, with the standard
deviation thought to be related to the large range of pore sizes found
in FCC particles. The developed methodology can be used to evaluate,
quantify and map heterogeneities in diffusional properties within
complex hierarchically porous materials.
2017-09-13 18:43:43
study self-diffusion
diffusional properties
macropore
pore sizes
Pore Network
map heterogeneities
Single-Molecule Fluorescence Microscopy
FCC particles
Local Diffusion Coefficients
pore network
feedstock-like probe molecule
Individual Catalyst Particle
nanometer accuracy
single-molecule fluorescence microscopy
diffusion coefficient