Langmuir,
Год журнала:
2024,
Номер
40(33), С. 17212 - 17238
Опубликована: Авг. 7, 2024
Plastics
are
widely
used
materials
in
our
daily
lives
and
various
industries
due
to
their
affordability
versatility.
The
massive
production
of
plastic
waste,
however,
has
recently
emerged
as
a
pressing
environmental
concern
across
all
media.
To
address
this,
emerging
technologies
being
explored
for
the
sustainable
valorization
postconsumer
wastes
including
thermochemical,
physical,
catalytic
processes
aimed
at
transforming
them
into
higher
value-added
products.
However,
chemical
recycling
mixed
poses
formidable
challenge
diverse
array
monomers
catalyst
systems
involved,
each
employing
distinct
mechanisms.
Complicating
matters
further
is
that
contaminants
reduce
efficacy,
requiring
rigorous
labor-intensive
separation
purification
extract
individual
streams
from
practical
waste
mixtures.
Consequently,
majority
such
mixtures
often
end
up
incineration
landfills,
perpetuating
societal
challenges,
leachate,
carbon
dioxide
emissions,
other
air
pollutants.
This
review
will
introduce
current
technical
developments
available
through
processes.
challenges
process
performance,
low
selectivity
desired
products,
deactivation
catalysis
also
discussed.
Promising
approaches
overcome
problems
suggested
future
research
directions.
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.
Chemical Society Reviews,
Год журнала:
2024,
Номер
53(14), С. 7309 - 7327
Опубликована: Янв. 1, 2024
Oxidative
degradation
is
a
powerful
method
to
degrade
plastics
into
oligomers
and
small
oxidized
products.
While
thermal
energy
has
been
conventionally
employed
as
an
external
stimulus,
recent
advances
in
photochemistry
have
enabled
photocatalytic
oxidative
of
polymers
under
mild
conditions.
This
tutorial
review
presents
overview
degradation,
from
its
earliest
examples
emerging
strategies.
briefly
discusses
the
motivation
development
with
focus
on
underlying
mechanisms.
Then,
we
will
examine
modern
studies
primarily
relevant
catalytic
degradation.
Lastly,
highlight
some
unique
using
unconventional
approaches
for
polymer
such
electrochemistry.
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Фев. 18, 2025
7
billion
of
9.2
tons
plastic
produced
becomes
waste
while
conventional
catalytic
recycling
methods
are
vulnerable
with
degraded
performance
and
intensive
energy
input.
Here,
a
hybrid
Zn/b-ZnO
catalyst,
together
the
specially-designed
microwave
reaction
system,
has
achieved
fast
upgrading
under
atmospheric
pressure
without
using
H2.
Bifunctional
ZnO
acts
as
absorber
substrate
in-situ
formed
Zn
clusters
promote
C-C
bond
cleavage
nearly
100%
upcycle
landfilled
mixtures
into
lubricant
base
oil
precursors
monomers.
Unprecedented
turnover
number
(250
gplastic
g−1catalyst)
depolymerisation
long-time
stability
over
50
successive
cycles
have
been
demonstrated,
8-time
higher
efficiency
compared
catalysis,
indicating
this
strategy
is
an
economical
approach
to
efficient
upcycling
plastics
towards
valuable
products.
Moreover,
catalyst
can
tolerate
high
contaminates,
even
still
be
converted
precursors,
which
never
reported
before.
Traditional
for
often
suffer
from
reduced
demands.
authors
demonstrate
highly
rapid
process
depolymerizing
monomers
microwave-assisted
catalysis
mild
conditions.
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 4570 - 4578
Опубликована: Март 4, 2025
Polyesters,
especially
polyethylene
terephthalate
(PET),
are
widely
used
in
plastic
bottles
and
clothing
fibers
because
of
their
stability
cost-effectiveness.
Upcycling
waste
polyesters
into
value-added
materials
not
only
solves
the
environmental
crisis
but
also
realizes
significant
economic
interests.
Here,
we
report
a
step-economic
two-step
catalytic
process
for
upcycling
polyester
materials,
specifically
PET,
1,4-cyclohexanedimethanol
(CHDM),
an
essential
monomer
functional
key
feedstock
liquid
crystal
industry.
The
combination
PET
methanolysis
hydrogenation
aromatic
rings
significantly
reduces
reaction
temperature
energy
consumption
depolymerization
which
introduces
remarkable
engineering
benefits.
By
developing
CO-resistant
bifunctional
Ru/MnO2
CuZnZr
mixed
oxide
catalyst
system,
is
demonstrated
to
be
converted
completely
with
final
yield
CHDM
up
78%.
implementation
transforming
holds
implications
advancing
value
chain
contributing
material
utilization
renewable
future.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(4), С. 2673 - 2684
Опубликована: Янв. 18, 2024
The
revalorization
of
incompatible
polymer
blends
is
a
key
obstacle
in
realizing
circular
economy
the
plastics
industry.
Polyolefin
waste
particularly
challenging
because
it
difficult
to
sort
into
its
constituent
components.
Untreated
polyethylene
and
polypropylene
typically
exhibit
poor
mechanical
properties
that
are
suitable
only
for
low-value
applications.
Herein,
we
disclose
simple
azidotriazine-based
grafting
agent
enables
polyolefin
be
directly
upcycled
high-performance
materials
by
using
reactive
extrusion
at
industrially
relevant
processing
temperatures.
Based
on
series
model
experiments,
azidotriazine
thermally
decomposes
form
triplet
nitrene
species,
which
subsequently
undergoes
complex
mixture
grafting,
oligomerization,
cross-linking
reactions;
strikingly,
oligomerization
reactions
proceed
through
formation
nitrogen-nitrogen
bonds.
When
applied
during
extrusion,
this
combination
leads
generation
amorphous,
phase-separated
nanostructures
tend
exist
polymer-polymer
interfaces.
These
act
as
multivalent
cross-linkers
reinforce
resulting
material,
leading
dramatically
improved
ductility
compared
with
untreated
blends,
along
high
dimensional
stability
temperatures
excellent
recyclability.
We
propose
unique
behavior
derived
from
thermomechanically
activated
reversibility
bonds
make
up
structures.
Finally,
scope
chemistry
demonstrated
applying
ternary
well
postconsumer
feedstocks.
Green Chemistry,
Год журнала:
2024,
Номер
26(5), С. 2384 - 2420
Опубликована: Янв. 1, 2024
While
our
society
is
facing
the
challenge
of
accumulating
plastic
waste,
this
review
discusses
recent
advances
towards
polymer
circularity
with
an
emphasis
on
manipulations
monomer–polymer
equilibrium
to
create
chemically
recyclable
polymers.
