The Journal of Physical Chemistry C,
Год журнала:
2022,
Номер
126(7), С. 3305 - 3313
Опубликована: Фев. 10, 2022
Over
the
past
decades,
first-principles-based
modeling
has
transformed
heterogeneous
catalysis.
Initially,
computational
provided
insights
into
nature
of
active
sites
and
catalytic
mechanisms,
soon
potential
to
predict
materials
with
desirable
properties
was
recognized.
As
today,
design
catalysts
is
a
mature
field.
At
same
time
continuous
developments
in
methodology
increased
availability
resources
indicate
significant
for
growth
future.
In
this
Perspective,
I
outline
three
directions
development
that
directly
address
shortcomings
today’s
catalyst
paradigms.
These
grand
challenges
are
(i)
machine
learning
AI
automated
discovery
catalysts,
(ii)
selective
modification
energy
surfaces,
(iii)
holistic
catalysts.
The
motivation
progress
each
area
given;
before
challenges,
current
state
art
long-term
goal
aspire
discussed.
If
these
goals
achieved,
described
contribution
have
transform
catalysis
will
lead
shift
from
an
experimentally
based
process
today
computationally
driven
Chemical Reviews,
Год журнала:
2022,
Номер
123(9), С. 6359 - 6411
Опубликована: Дек. 2, 2022
The
direct
transformation
of
methane
to
methanol
remains
a
significant
challenge
for
operation
at
larger
scale.
Central
this
is
the
low
reactivity
conditions
that
can
facilitate
product
recovery.
This
review
discusses
issue
through
examination
several
promising
routes
and
an
evaluation
performance
targets
are
required
develop
process
We
explore
methods
currently
used,
emergence
active
heterogeneous
catalysts
their
design
reaction
mechanisms
provide
critical
perspective
on
future
operation.
Initial
experiments
discussed
where
identification
gas
phase
radical
chemistry
limited
further
development
by
approach.
Subsequently,
new
class
catalytic
materials
based
natural
systems
such
as
iron
or
copper
containing
zeolites
were
explored
milder
conditions.
key
issues
these
technologies
conversion
often
overoxidation
products.
Despite
this,
interest
high
in
wider
appeal
effective
route
products
from
C–H
activation,
particularly
with
need
transition
net
carbon
zero
renewable
sources
exciting.
Science,
Год журнала:
2021,
Номер
374(6565), С. 308 - 315
Опубликована: Сен. 16, 2021
Selectivity
control
in
zeolite
synthesis
Zeolites
are
widely
used
many
industrial
applications,
but
despite
decades
of
research,
their
still
relies
on
trial-and-error
approaches.
Complex
nucleation
mechanisms
and
topological
diversity
lead
to
strong
phase
competition,
complicating
the
issue
rational
design
synthesis.
Using
atomistic
simulations,
literature
mining,
human-computer
interaction,
synthesis,
characterization,
Schwalbe-Koda
et
al
.
developed
a
computational
strategy
that
enables
priori
selectivity
(see
Perspective
by
Chaikittisilp
Okubo).
This
approach
uses
several
metrics
for
designing
organic
structure–directing
agents
crystallize
target
zeolites
with
controlled
competition
intergrowth.
These
results
may
have
profound
implications
materials
science
community
if
this
method
is
shown
be
successful
practically
useful
uncommon
zeolites.
—YS
JACS Au,
Год журнала:
2024,
Номер
4(1), С. 197 - 215
Опубликована: Янв. 4, 2024
A
key
challenge
for
metal-exchanged
zeolites
is
the
determination
of
metal
cation
speciation
and
nuclearity
under
synthesis
reaction
conditions.
Copper-exchanged
zeolites,
which
are
widely
used
in
automotive
emissions
control
potential
catalysts
partial
methane
oxidation,
have
particular
evidenced
a
wide
variety
Cu
structures
that
observed
to
change
with
exposure
conditions,
zeolite
composition,
topology.
Here,
we
develop
predictive
models
CHA,
MOR,
BEA,
AFX,
FER
topologies
using
interatomic
potentials,
quantum
chemical
calculations,
Monte
Carlo
simulations
interrogate
this
vast
configurational
compositional
space.
Model
predictions
rationalize
experimentally
differences
between
Cu-zeolites
wide-body
literature,
including
populations,
structural
variations,
methanol
per
yields.
Our
results
show
both
topological
features
commonly
Al-siting
biases
MOR
increase
population
binuclear
sites,
explaining
small
mononuclear
sites
these
materials
relative
other
such
as
CHA
BEA.
Finally,
machine
learning
classification
model
determine
preference
form
or
at
different
Al
configurations
200
international
database.
reveal
several
extreme
ends
vs
spectrum,
highlighting
synthetic
options
realization
strong
preferences.
ACS Catalysis,
Год журнала:
2022,
Номер
12(9), С. 5060 - 5076
Опубликована: Апрель 14, 2022
Zeolites
and
metal-zeolites
are
a
class
of
porous
materials
that
have
been
widely
utilized
in
industry.
So
far,
several
fundamental
questions
relating
to
the
dynamic
evolution
zeolite
framework
metal-zeolite
interface
remain
unanswered.
Contrary
classical
view
zeolites
as
static,
rigid,
changeless
material,
atoms
foreign
metals
can
dynamically
interconvert
under
pretreatment
or
reaction
conditions,
making
it
difficult
identify
real
active
centers
mechanisms.
With
development
characterization
techniques
theoretical
calculations,
more
profound
understanding
at
atomic
scale
has
achieved.
This
critical
Review
will
feature
recent
progress
metal-zeolites,
mainly
focusing
on
T–O–T
bonds
breaking
formation,
metal
valence
state
transformation,
phase
evolution,
migration.
We
compare
these
proposed
mechanisms
analyze
their
suitability
distinct
experimental
conditions.
highlight
identification
sites
catalytic
mechanism
should
be
cautious
consider
Finally,
we
summarize
usages
limitations
different
characteristic
techniques,
propose
some
future
research
directions
about
hope
bridge
gaps
between
knowledge
achieved
characterizations
nature
guide
zeolite-based
synthesis,
modification,
application.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(23)
Опубликована: Апрель 4, 2024
Abstract
In
the
past,
Cu‐oxo
or
‐hydroxy
clusters
hosted
in
zeolites
have
been
suggested
to
enable
selective
conversion
of
methane
methanol,
but
impact
active
site's
stoichiometry
and
structure
on
methanol
production
is
still
poorly
understood.
Herein,
we
apply
theoretical
modeling
conjunction
with
experiments
study
these
two
factors
partial
oxidation
Cu‐exchanged
zeolite
SSZ‐13.
Phase
diagrams
developed
from
first‐principles
suggest
that
Cu‐hydroxy
dimers
are
stabilized
when
O
2
N
used
activate
catalyst,
respectively.
We
confirm
predictions
experimentally
determine
a
stepwise
process,
can
convert
twice
as
much
compared
Cu‐hydroxyl
dimers.
Our
models
rationalize
how
Cu‐di‐oxo
up
molecules
while
Cu‐di‐hydroxyl
only
one
molecule
per
catalytic
cycle.
These
findings
imply
Cu
clusters,
at
least
oxo
group
hydroxyl
groups
needed
This
simple
structure–activity
relationship
allows
intuitively
understand
potential
small
oxygenated
hydroxylated
transition
metal
methanol.
The Chemical Record,
Год журнала:
2025,
Номер
unknown
Опубликована: Янв. 16, 2025
Abstract
Direct
methane
to
methanol
conversion
is
a
dream
reaction
in
industrial
chemistry,
which
takes
inspiration
from
the
biological
production
catalysed
by
monooxygenase
enzymes
(MMOs).
Over
years,
extensive
studies
have
been
conducted
on
this
topic
bioengineering
MMOs,
and
tailoring
methods
isolate
MMOs
active
form.
Similarly,
remarkable
achievements
noted
other
activation
strategies
such
as
use
of
heterogeneous
catalysts
or
molecular
catalysts.
In
review,
we
outline
metabolism
performed
methanotrophs
detail
latest
advancements
site
structures
catalytic
mechanisms
both
types
MMOs.
Also,
recent
progress
bioinspired
approaches
using
various
catalysts,
especially
first‐row
transition
metal
zeolites
mechanistic
insights
are
discussed.
addition,
complexes
“Periana
catalyst”
for
through
methyl
ester
formation
presence
strong
acids
also
detailed.
Compared
zeolites‐mediated
field,
utilisation
application
still
its
nascent
phase
further
research
required
overcome
limitations
these
effectively.
ACS Catalysis,
Год журнала:
2022,
Номер
12(11), С. 6418 - 6433
Опубликована: Май 16, 2022
In
this
work,
a
kinetic
model
is
developed
for
the
reduction
of
CuII
sites
by
NO
+
NH3
and
reoxidation
NH3-solvated
CuI
O2
in
Cu-SSZ-13.
Fourier
transform
infrared
(FTIR)
spectroscopy
spatially
resolved
capillary
inlet
mass
spectrometry
(SpaciMS)
measurements
during
transient
reactor
experiments
are
utilized
to
identify
rate
parameters
associated
with
RHC
(reduction
half-cycle),
proposed
occur
via
two
distinct
pathways
involving
adsorbed
gas-phase
NH3.
The
resulting
validated
using
spatiotemporal
N2
covering
wide
range
temperatures
(200–450
°C)
space
velocities
(53
000–640
000
h–1).
N2O
formation
observed
modeled
RHC,
quantitative
validation
under
standard
selective
catalytic
(SCR)
conditions.
Experimentally
measured
enthalpic
entropic
changes
adsorption
on
(ZCu(NH3)2)
complexes
[Kamasamudram,
K.
Catal.
Today
2010,
151(3–4),
212−222],
along
activation
energies
estimated
computationally
intercage
diffusion
ZCu(NH3)2
[Paolucci,
C.
Science
2017,
357(6
354),
898−903],
incorporated
into
mean
field
low-temperature
oxidation
half-cycle
(OHC).
Significant
release
isothermal
sites,
attributed
desorption
ligands
from
dimers
(Z2Cu2(NH3)4O2).
Reduction
these
dimeric
leads
consumption
one
NO/CuII,
contradicting
expected
stoichiometry.
Inclusion
global
Arrhenius
titration
Z2Cu2(NH3)4O2
provides
accurate
representations
SCR
reduced
oxidized
catalysts,
predicting
between
150
250
°C
as
function
hydrothermal
aging.
Deactivation
at
high
pressures,
superoxo
amino
(ZCu(NH3)3OO*)
[Negri,
J.
Am.
Chem.
Soc.
2020,
142(37),
15884−15896].
redox
presented
here
foundational
description
active
site
SCR,
combining
recent
kinetic,
spectroscopic,
computational
findings
mechanism
over
ACS Catalysis,
Год журнала:
2022,
Номер
12(4), С. 2454 - 2462
Опубликована: Фев. 3, 2022
Catalytic
reaction
systems
for
the
direct
conversion
of
methane
to
methanol
have
been
previously
developed
using
Cu
zeolites.
Among
these
materials,
Cu-CHA
has
reported
show
relatively
high
catalytic
performance
during
CH4–O2–H2O
mixtures,
although
this
activity
varies
with
composition.
In
present
study,
four
catalysts
having
different
compositions
and
levels
were
prepared,
redox
properties
local
structures
specimens
analyzed
in
situ
X-ray
absorption
fine
structure
UV–vis
diffuse
reflectance
spectroscopies
conjunction
a
mixture.
The
relationships
between
rates
materials
activities
(as
reflected
turnover
frequency
(TOF)
CH4
oxidation)
assessed,
analysis
showed
that
reduction
rate
was
highly
correlated
activity.
data
also
suggested
Cu2+
is
associated
activation
C–H
bonds
CH4,
which
rate-determining
step
overall
reaction.
effects
on
selectivity
CH3OH,
TOF
value,
studied.
Those
samples
proportions
ions
coordinated
six-membered
rings
(Z2Cu)
CHA
framework
exhibited
higher
than
[CuOH]+
eight-membered
(ZCuOH),
values
former
not
those
latter
because
slower
species.
catalyses
can
be
attributed
difference
Cu2Ox
active
formed
Z2Cu-rich
ZCuOH-rich
samples.