Angewandte Chemie,
Год журнала:
2023,
Номер
136(6)
Опубликована: Окт. 2, 2023
Abstract
The
structural
and
morphological
characterization
of
individual
catalyst
particles
for
olefin
polymerization,
as
well
the
reverse
process
polyolefin
decomposition,
can
provide
an
improved
understanding
how
these
materials
operate
under
relevant
reaction
conditions.
In
this
review,
we
discuss
emerging
analytical
toolbox
2D
3D
chemical
imaging
techniques
that
is
suitable
investigating
chemistry
reactivity
related
systems.
While
synchrotron‐based
X‐ray
microscopy
still
provides
unparalleled
spatial
resolutions
in
3D,
a
number
laboratory‐based
techniques,
most
notably
focused
ion
beam‐scanning
electron
microscopy,
confocal
fluorescence
infrared
photoinduced
force
nano‐computed
tomography,
have
helped
to
significantly
expand
arsenal
tools
available
scientists
heterogeneous
catalysis
polymer
science.
terms
future
research,
review
outlines
role
impact
situ
operando
(spectro−)microscopy
experiments,
involving
sophisticated
reactors
online
reactant
product
analysis,
obtain
real‐time
information
on
formation,
mobility
phases
within
single
particles.
Furthermore,
potential
optical
highlighted
high‐throughput
polymerization
decomposition
catalysts.
By
combining
with,
example,
staining
methodologies,
selective
probe
molecules
particle
sorting
approaches,
representative
structure–activity
relationships
be
derived
at
level
Chemical Reviews,
Год журнала:
2024,
Номер
124(16), С. 9457 - 9579
Опубликована: Авг. 16, 2024
The
large
production
volumes
of
commodity
polyolefins
(specifically,
polyethylene,
polypropylene,
polystyrene,
and
poly(vinyl
chloride)),
in
conjunction
with
their
low
unit
values
multitude
short-term
uses,
have
resulted
a
significant
pressing
waste
management
challenge.
Only
small
fraction
these
is
currently
mechanically
recycled,
the
rest
being
incinerated,
accumulating
landfills,
or
leaking
into
natural
environment.
Since
are
energy-rich
materials,
there
considerable
interest
recouping
some
chemical
value
while
simultaneously
motivating
more
responsible
end-of-life
management.
An
emerging
strategy
catalytic
depolymerization,
which
portion
C-C
bonds
polyolefin
backbone
broken
assistance
catalyst
and,
cases,
additional
molecule
reagents.
When
products
molecules
materials
higher
own
right,
as
feedstocks,
process
called
upcycling.
This
review
summarizes
recent
progress
for
four
major
upcycling
strategies:
hydrogenolysis,
(hydro)cracking,
tandem
processes
involving
metathesis,
selective
oxidation.
Key
considerations
include
macromolecular
reaction
mechanisms
relative
to
mechanisms,
design
transformations,
effect
conditions
on
product
selectivity.
Metrics
describing
critically
evaluated,
an
outlook
future
advances
described.
Applied Physics Reviews,
Год журнала:
2025,
Номер
12(1)
Опубликована: Янв. 10, 2025
Scaling
up
photocatalytic
systems
for
large-scale
hydrogen
generation
holds
transformative
potential
sustainable
energy
but
faces
significant
technical
and
economic
challenges
in
transitioning
from
lab-scale
experiments
to
industrial
applications.
This
review
delves
into
recent
innovations
that
drive
progress
this
field,
including
advanced
materials
developed
improved
efficiency
stability,
as
well
innovative
reactor
designs
optimize
light
capture
reactant
flow.
It
also
examines
practical
strategies
the
integration
of
these
with
renewable
sources,
focusing
on
their
scalability
cost-effectiveness.
Key
addressed
include
mass
transport
limitations,
utilization,
catalyst
longevity,
accompanied
by
emerging
solutions
aim
overcome
hurdles.
The
comprehensively
explores
intersection
technological
advancements
feasibility,
emphasizing
environmental
considerations
necessary
implementation
production.
Emphasizing
most
developments
strategic
approaches,
outlines
a
pathway
advancing
technologies.
Chemical Science,
Год журнала:
2024,
Номер
15(23), С. 8606 - 8624
Опубликована: Янв. 1, 2024
Electrochemistry
shows
promising
new
avenues
in
the
recycling
of
polymeric
materials.
This
work
reviews
electrochemical
depolymerization,
post-polymerization
functionalization,
and
paired
catalysis,
highlighting
future
challenges
opportunities.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(26)
Опубликована: Апрель 22, 2024
Catalytic
upcycling
of
polyolefins
into
high-value
chemicals
represents
the
direction
in
end-of-life
plastics
valorization,
but
poses
great
challenges.
Here,
we
report
synthesis
a
tandem
porous
catalyst
via
micelle
cascade
assembly
strategy
for
selectively
catalytic
cracking
polyethylene
olefins
at
low
temperature.
A
hierarchically
silica
layer
from
mesopore
to
macropore
is
constructed
on
surface
microporous
ZSM-5
nanosheets
through
dynamic
micelles.
The
outer
arrays
can
adsorb
bulky
quickly
by
capillary
and
hydrophobic
effects,
enhancing
diffusion
access
active
sites.
middle
mesopores
present
nanoconfinement
space,
pre-cracking
intermediates
weak
acid
sites,
which
then
transport
zeolites
micropores
further
strong
Brønsted
acidic
structures,
mimicking
biomimetic
protease
clefts,
ideally
match
steps
polyolefins,
thus
suppressing
coke
formation
facilitating
product
escape.
As
result,
light
hydrocarbons
(C
Nature Chemical Engineering,
Год журнала:
2024,
Номер
1(9), С. 565 - 575
Опубликована: Авг. 28, 2024
Abstract
Since
the
dawn
of
agitated
brewing
in
Paleolithic
era,
effective
mixing
has
enabled
efficient
reactions.
Emerging
catalytic
chemical
polyolefin
recycling
processes
present
unique
challenges,
considering
that
polymer
melt
a
viscosity
three
orders
magnitude
higher
than
honey.
The
lack
protocols
to
achieve
may
have
resulted
suboptimal
catalyst
effectiveness.
In
this
study,
we
tackled
hydrogenolysis
commercial-grade
high-density
polyethylene
and
polypropylene
show
how
different
stirring
strategies
can
create
differences
up
85%
40%
effectiveness
selectivity,
respectively.
reaction
develops
near
H
2
–melt
interface,
with
extension
interface
access
particles
main
performance
drivers.
Leveraging
computational
fluid
dynamics
simulations,
identified
power
number
15,000–40,000
maximize
factor
optimize
parameters.
This
temperature-
pressure-independent
model
holds
across
range
1–1,000
Pa
s.
Temperature
gradients
quickly
become
relevant
for
reactor
scale-up.
ACS Sustainable Chemistry & Engineering,
Год журнала:
2023,
Номер
12(1), С. 178 - 191
Опубликована: Дек. 16, 2023
Synthetic
polyolefinic
plastics
comprise
one
of
the
largest
shares
global
plastic
waste,
which
is
being
targeted
for
chemical
recycling
by
depolymerization
to
monomers
and
small
molecules.
One
promising
method
solid-state
under
ambient
conditions
in
a
ball-mill
reactor.
In
this
paper,
we
elucidate
kinetic
phenomena
mechanochemical
poly(styrene).
Styrene
produced
process
at
constant
rate
selectivity
alongside
minor
products,
including
oxygenates
like
benzaldehyde,
via
mechanisms
analogous
those
involved
thermal
oxidative
pyrolysis.
Continuous
monomer
removal
during
reactor
operation
critical
avoiding
repolymerization,
promoting
effects
are
exhibited
iron
surfaces
molecular
oxygen.
Kinetic
independence
between
weight
reduction
was
observed,
despite
both
processes
originating
from
same
driving
force
collisions.
Phenomena
across
multiple
length
scales
shown
be
responsible
differences
reactivity
due
grinding
parameters
reactant
composition.
Catalysis Science & Technology,
Год журнала:
2024,
Номер
14(4), С. 894 - 902
Опубликована: Янв. 1, 2024
Confocal
fluorescence
microscopy,
infrared
spectroscopy,
UV-Vis
spectroscopy
and
nuclear
magnetic
resonance
are
used
to
study
the
reaction
intermediates
during
cracking
of
polypropylene
over
a
fresh
fluid
catalytic
catalyst.
The Journal of Physical Chemistry C,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 10, 2025
Plastic
waste
is
a
major
environmental
issue;
converting
it
directly
into
valuable
chemicals
by
using
catalysts
promising
alternative
to
plastic
recycling.
Here,
we
report
the
selective
catalytic
cracking
of
polypropylene
(PP),
typical
commodity
plastic,
high-value
light
olefins
(C2–C5),
below
pyrolytic
temperature
(290
°C)
and
without
external
hydrogen
supply,
zeolite
catalysts.
Among
H+-form
zeolites
with
different
structures,
HMFI
showed
highest
yields
hydrocarbons
which
(C2–C5)
were
products.
The
HMFI-catalyzed
PP
conversion
was
applicable
upcycling
model
waste,
resulting
in
61.9%
hydrocarbon
yield.
results
situ
IR
experiments
small
amount
Brønsted
acid
sites
suggested
that
on
surface
are
indispensable
for
posited
be
active
short-chain
(oligomeric)
species
as
intermediate
Density
functional
theory
analyses
conducted
determine
plausible
reaction
pathways
adopting
2,4-dimethylheptene
shortest
unit
oligomeric
species.
obtained
show
β-scission
isobutene
propylene
(or
propyl
alkoxide
group)
via
carbocation
intermediates
an
activation
energy
118
kJ
mol–1.
Operando
UV–vis
under
conditions,
combined
ex
1H
NMR
13C
spent
catalyst,
some
further
converted
or
heavy
aromatics
(coke
deposit),
probably
carbenium
ion
