ACS Applied Nano Materials,
Год журнала:
2024,
Номер
7(7), С. 7018 - 7027
Опубликована: Март 21, 2024
The
performance
of
metal
sites
in
terms
their
formation,
evolution,
and
deactivation
is
strongly
influenced
by
the
properties
supports
during
catalysis.
Nanomaterials
offer
a
tailorable
size,
shape,
composition,
along
with
large
surface
area,
high
fraction
atoms,
unique
electronic
properties,
thereby
significantly
improving
efficiency,
selectivity,
stability,
versatility
catalytic
processes.
In
direct
dehydrogenation
propane
(PDH)
reactions,
activity,
durability
catalysts
face
challenges
due
to
reaction
temperature
harsh
atmosphere
that
accompanies
presence
reducible
reactants.
Herein,
bimetallic
platinum–zinc
(PtZn)
were
synthesized
on
various
silica
nanomaterials
investigate
correlation
between
nanoscale
PDH
performance.
Among
being
explored,
including
amorphous
SiO2
particles,
mesoporous
SBA-15,
microporous
silicate-1,
MCM-41,
MCM-41
stood
out
its
distinctive
advantages,
specific
well-portioned
pore
size
distribution,
an
appropriate
amount
strength
acidic
sites.
Operating
at
600
°C,
catalyst
exhibited
notable
propene
production
rate
approximately
37.3
mmol·gcat–1·h–1.
This
was
coupled
outstanding
initial
conversion
(39.2%)
selectivity
(97.7%)
reaction.
characterization
results
highlighted
exceptional
dispersion
PtZn
support,
showing
remarkable
resistance
coking
sintering
throughout
These
attributes
exceeded
those
observed
other
supports.
Science,
Год журнала:
2024,
Номер
383(6689), С. 1325 - 1331
Опубликована: Март 21, 2024
Propylene
production
through
propane
dehydrogenation
(PDH)
is
endothermic,
and
high
temperatures
required
to
achieve
acceptable
conversions
lead
low
selectivity
severe
carbon-induced
deactivation
of
conventional
catalysts.
We
developed
a
catalyst-membrane
system
that
removes
the
hydrogen
by-product
can
thus
exceed
equilibrium
limits.
In
this
codesigned
system,
silica/alumina
(SiO
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Авг. 2, 2024
Designing
highly
active
and
stable
catalytic
sites
is
often
challenging
due
to
the
complex
synthesis
procedure
agglomeration
of
during
high-temperature
reactions.
Here,
we
report
a
facile
two-step
method
synthesize
Pt
clusters
confined
by
In-modified
ZSM-5
zeolite.
In-situ
characterization
confirms
that
In
located
at
extra-framework
position
as
In+,
are
stabilized
In-ZSM-5
The
resulting
in
show
excellent
propane
conversion,
propylene
selectivity,
stability,
outperforming
monometallic
Pt,
In,
bimetallic
PtIn
alloys.
incorporation
In+
neutralizes
Brønsted
acid
inhibit
side
reactions,
well
tunes
electronic
properties
facilitate
activation
desorption.
strategy
combining
precious
metal
with
cation-exchanged
zeolites
opens
avenue
develop
heterogeneous
catalysts
for
other
reaction
systems.
procedures
Here
authors
present
ZSM-5,
superior
dehydrogenation
performance.
Propane
dehydrogenation
(PDH)
Pt-based
catalysts
are
facing
the
serious
challenge
of
coke
deactivation.
The
locations
would
greatly
influence
formation,
while
detailed
mechanism
is
not
fully
explored.
Herein,
mechanisms
on
different
including
Al2O3,
Sn,
Pt,
and
Pt-Sn
sites
were
deeply
investigated
via
in
situ
Fourier
transform
infrared
spectroscopy
(FTIR)
technology,
key
factors
triggering
catalyst
deactivation
proposed.
Excessive
propyl
species
a
crucial
initial
step
formation
coke,
whether
at
metal
or
supports.
These
Al2O3
supports
then
cyclize
to
form
monocyclic
aromatic
bicyclic
species,
those
SnOx
species.
As
for
supported
PtSn
catalysts,
strong
function
interaction
between
Pt
trigger
complex
mechanism.
surface
with
saturated
coordination
prone
deposition,
leading
rapid
stage
reaction.
However,
low-coordination
ultra-small
size
found
be
highly
resistant
PDH
reaction,
which
selectively
catalytic
PDH.
Owing
metal-support
interaction,
extensive
active
hydrogen
generated
from
can
regulate
precursors
Furthermore,
effect
co-feed
deposition
also
inhibits
results
higher
H/C
ratio
(3.96)
precursors.
This
study
enhance
understanding
PDH,
important
designing
efficient
catalysts.
Journal of the American Chemical Society,
Год журнала:
2024,
Номер
146(35), С. 24358 - 24367
Опубликована: Авг. 21, 2024
Crystalline
zeolites
have
been
proven
to
be
excellent
supports
for
confining
subnanometric
metal
catalysts
boost
the
propane
dehydrogenation
(PDH)
reaction.
However,
introduced
metallic
species
may
suffer
from
severe
sintering
and
limited
stability
during
catalytic
process,
especially
when
utilizing
an
industrial
impregnation
method
incorporation.
In
this
study,
we
developed
a
new
type
of
support
based
on
amorphous
protozeolite
(PZ),
taking
advantage
its
adjustable
silanol
chemistry
zeolitic
microporous
characteristic
stabilizing
atomically
dispersed
PtSn
catalyst
via
simple,
cost-effective
coimpregnation
process.
The
combination
X-ray
absorption
spectroscopy,
photoelectron
in
situ
diffuse
reflectance
infrared
Fourier
transform
spectroscopy
under
CO
atmosphere,
density
functional
theory
calculations
confirmed
formation
highly
active
Ptδ+-Ox-Sn
PtSn/PZ.
PtSn/PZ
exhibited
high
conversion
45.4%
propylene
selectivity
99%
(WHSV=
3.6
h–1,
550
°C),
with
apparent
rate
coefficient
565
molC3H6·gPt–1·h–1·bar–1
at
WHSV
108
presenting
top-level
performance
among
state-of-the-art
Pt-based
prepared
by
synthesis
methods.
determined
chemical
state
species,
showing
change
sites
alloy
decreasing
supports.
This
work
provides
general
strategy
using
silanol-rich
as
various
simple
also
offers
effective
way
fine
tailoring
silanol-engineered
approach.
ACS Catalysis,
Год журнала:
2025,
Номер
unknown, С. 3215 - 3226
Опубликована: Фев. 7, 2025
Structural
transformation
under
in
situ
reaction
conditions
plays
a
vital
role
heterogeneous
catalytic
performance,
especially
caused
by
metal
migration.
However,
the
migration
of
active
components
often
leads
to
irreversible
structural
disruption
at
high
temperatures,
which
could
be
associated
with
deactivation
catalysts.
Here,
we
report
low-melting-point
Zn
migration-mediated
strategy
synthesize
ultrastable
isolated
PtFe3
sites
anchored
MFI
zeolite
for
propane
direct
dehydrogenation.
The
optimized
catalyst
exhibited
superior
specific
activity
36.5
mol
C3H6
molPt–1
s–1
propylene
selectivity
above
99%
550
°C.
Moreover,
dehydrogenation
remained
stable
after
over
400
h
on
stream
low
rate
constant
0.001
h–1
industrial
580
In
characterizations
demonstrated
that
Fe3+
species
were
conducive
rearrangement
electronic
configuration
unoccupied
5d
states
Pt
atoms
form
electron-deficient
sites.
This
afford
insights
into
dynamic
evolution
preparation
processes.
ACS Catalysis,
Год журнала:
2023,
Номер
13(22), С. 14737 - 14745
Опубликована: Ноя. 1, 2023
Propane
dehydrogenation
(PDH)
presents
a
promising
alternative
to
naphtha
steam
cracking
processes
for
propene
production.
However,
the
current
commercial
catalysts
are
plagued
by
toxicity
of
Cr
(VI)
and
exorbitant
cost
Pt.
We
have
developed
an
efficient,
eco-friendly,
cost-effective
catalyst
(CoOx@MFI)
in
which
reduction-resistant
CoOx
clusters
embedded
situ
into
zeolite
framework.
This
exhibits
good
catalytic
performances
(59.0%
propane
conversion
93.0%
selectivity)
PDH
reactions,
surpassing
most
Co-based
competing
with
Pt-based
ones.
Crucially,
both
spectroscopy
theoretical
calculations
demonstrate
that
MFI
zeolite-stabilized
Co–O
moieties
highly
favorable
C–H
bond
activation
via
O
atom
as
Lewis
base,
can
attach
H
generate
[CoOH]+
intermediate
remarkable
efficiency.
