Angewandte Chemie,
Год журнала:
2023,
Номер
135(44)
Опубликована: Сен. 12, 2023
Abstract
Copper(II)‐containing
mordenite
(CuMOR)
is
capable
of
activation
C−H
bonds
in
C
1
‐C
3
alkanes,
albeit
there
are
remarkable
differences
between
the
functionalization
ethane
and
propane
compared
to
methane.
The
reaction
with
CuMOR
results
formation
ethylene
propylene,
while
methane
predominantly
yields
methanol
dimethyl
ether.
By
combining
situ
FTIR
MAS
NMR
spectroscopies
as
well
time‐resolved
Cu
K‐edge
X‐ray
absorption
spectroscopy,
mechanism
was
derived,
which
differs
significantly
for
each
alkane.
propylene
proceeds
via
oxidative
dehydrogenation
corresponding
alkanes
selectivity
above
95
%
85
propane.
stable
π‐complexes
olefins
I
sites,
formed
upon
reduction
II
‐oxo
species,
protects
from
further
oxidation
and/or
oligomerization.
This
different
methane,
hydroxylation
leading
surface
methoxy
species
bonded
zeolite
framework.
Our
findings
constitute
one
major
steps
direct
conversion
important
commodities
open
a
novel
research
direction
aiming
at
selective
synthesis
olefins.
Angewandte Chemie International Edition,
Год журнала:
2023,
Номер
62(44)
Опубликована: Сен. 12, 2023
Copper(II)-containing
mordenite
(CuMOR)
is
capable
of
activation
C-H
bonds
in
C1
-C3
alkanes,
albeit
there
are
remarkable
differences
between
the
functionalization
ethane
and
propane
compared
to
methane.
The
reaction
with
CuMOR
results
formation
ethylene
propylene,
while
methane
predominantly
yields
methanol
dimethyl
ether.
By
combining
situ
FTIR
MAS
NMR
spectroscopies
as
well
time-resolved
Cu
K-edge
X-ray
absorption
spectroscopy,
mechanism
was
derived,
which
differs
significantly
for
each
alkane.
propylene
proceeds
via
oxidative
dehydrogenation
corresponding
alkanes
selectivity
above
95
%
85
propane.
stable
π-complexes
olefins
CuI
sites,
formed
upon
reduction
CuII
-oxo
species,
protects
from
further
oxidation
and/or
oligomerization.
This
different
methane,
hydroxylation
leading
surface
methoxy
species
bonded
zeolite
framework.
Our
findings
constitute
one
major
steps
direct
conversion
important
commodities
open
a
novel
research
direction
aiming
at
selective
synthesis
olefins.
Chemical Science,
Год журнала:
2024,
Номер
15(27), С. 10308 - 10349
Опубликована: Янв. 1, 2024
Recent
progresses
in
Cu–oxygen
adducts
towards
recalcitrant
C–H
activation
are
reviewed
with
focus
on
Cu
metalloenzymes
and
bioinspired
synthetic
models,
mono-
to
polynuclear
complexes,
working
under
homogeneous
heterogeneous
catalytic
conditions.
Catalysis Today,
Год журнала:
2024,
Номер
436, С. 114729 - 114729
Опубликована: Апрель 15, 2024
Ethylene,
propylene,
and
benzene
were
investigated
as
molecules
for
extracting
methoxy
intermediate
species
formed
during
the
cyclic
partial
oxidation
of
methane
in
Cu-exchanged
zeolites,
promising
materials
step-wise
methane-to-methanol
(MTM)
reaction.
13C-labeled
reaction
studies
reveal
that
alkenes
preferentially
undergo
oligomerization
followed
by
cracking,
while
is
successfully
methylated,
forming
toluene.
Benzene
methylation
further
showcases
methyl
to
behave
similar
surface
on
Brønsted
acid
sites
methanol-to-hydrocarbon
(MTH)
However,
only
able
extract
a
fraction
compared
methanol
produced
with
water
extraction,
indicating
either
steric
or
intrinsic
mechanistic
effects
limit
full
potential
pool
inside
framework.
We
infer
presence
reactive
generated
under
conditions,
revealing
their
synthetic
platform
form
additional
products
from
methane.
ACS Catalysis,
Год журнала:
2024,
Номер
unknown, С. 17434 - 17444
Опубликована: Ноя. 12, 2024
Fe-containing
zeolite
catalysts
are
active
in
N2O
decomposition
and
direct
oxidation
of
unreactive
methane.
Except
for
the
well-known
ability
that
acid
sites
realize
subsequent
reaction
methanol
to
hydrocarbon,
roles
acidic
protons
methane
have
not
been
studied
regarding
formation
Fe
components
reactivity
reaction.
Herein,
on
premise
comparable
total
Al
contents,
acidity
one-pot
synthesized
Fe-AEI
ion-exchanged
Fe/AEI
zeolites
was
adjusted
by
various
Na
catalytic
activity
reactions
compared
under
different
conditions.
Ultraviolet–visible
(UV–vis)
spectra
at
25–500
°C
as-synthesized
performance
corresponding
conditions
were
combined
clarify
potential
species.
Acidic
proton
favorable
species
zeolite.
However,
H-type
zeolite,
thermal
treatment
high
temperatures
prone
dealuminate,
reduced
number
anchors
Fe3+
attachment,
resulted
inactive
FexOy.
Furthermore,
contrast
robust
adsorption
capacity
Na+,
exhibited
weak
competition
with
thus
contributed
higher
Our
findings
highlighted
importance
species,
frail
feasibility
tandem
hydrocarbon.
Angewandte Chemie,
Год журнала:
2024,
Номер
136(45)
Опубликована: Июль 26, 2024
Abstract
The
CH
4
oxidation
performance
of
Cu‐chabazite
zeolites
characterized
by
distinct
Si/Al
ratios
and
Cu
loadings
has
been
studied
the
observed
variations
in
reactivity
have
correlated
to
differences
nature
formed
active
centers.
Plug
flow
reactor
tests,
situ
Fourier‐transform
infrared,
X‐ray
absorption
spectroscopy
demonstrate
that
a
decrease
loading
shifts
reactivity/redox
profile
higher
temperatures
increases
3
OH
selectivity
Cu‐efficiency.
In
electron
paramagnetic
resonance,
Raman,
ultraviolet‐visible,
photoluminescence
spectroscopies
reveal
this
behavior
is
associated
with
presence
monomeric
sites,
including
bare
2+
[CuOH]
+
present
at
low
ratio
loading.
Formation
two
[Cu
2
(μ‐O)]
moieties
or
forces
these
trends
into
opposite
direction.
Operando
resonance
ultraviolet‐visible
show
apparent
activation
energy
species
decreases
increasing
ratio,
whereas
one
dimeric
centers
unaffected.
