Journal of the American Chemical Society,
Год журнала:
2017,
Номер
139(42), С. 14961 - 14975
Опубликована: Сен. 25, 2017
Cu-exchanged
zeolites
possess
active
sites
that
are
able
to
cleave
the
C–H
bond
of
methane
at
temperatures
≤200
°C,
enabling
its
selective
partial
oxidation
methanol.
Herein
we
explore
this
process
over
Cu-SSZ-13
materials.
We
combine
activity
tests
and
X-ray
absorption
spectroscopy
(XAS)
thoroughly
investigate
influence
reaction
parameters
material
elemental
composition
on
productivity
Cu
speciation
during
key
steps.
find
CuII
moieties
responsible
for
conversion
formed
in
presence
O2
high
temperature
together
with
prolonged
activation
time
increases
population
such
sites.
evidence
a
linear
correlation
between
reducibility
materials
their
methanol
productivity.
By
optimizing
conditions
composition,
reach
as
0.2
mol
CH3OH/mol
(125
μmol/g),
highest
value
reported
date
Cu-SSZ-13.
Our
results
clearly
demonstrate
populations
2Al
Z2CuII
6r,
favored
low
values
both
Si:Al
Cu:Al
ratios,
inhibit
performance
by
being
inactive
conversion.
Z[CuIIOH]
complexes,
although
shown
be
inactive,
identified
precursors
methane-converting
critical
examination
catalytic
spectroscopic
evidence,
propose
different
possible
routes
active-site
formation.
Chemical Reviews,
Год журнала:
2018,
Номер
118(10), С. 4981 - 5079
Опубликована: Апрель 16, 2018
Metal
species
with
different
size
(single
atoms,
nanoclusters,
and
nanoparticles)
show
catalytic
behavior
for
various
heterogeneous
reactions.
It
has
been
shown
in
the
literature
that
many
factors
including
particle
size,
shape,
chemical
composition,
metal–support
interaction,
metal–reactant/solvent
interaction
can
have
significant
influences
on
properties
of
metal
catalysts.
The
recent
developments
well-controlled
synthesis
methodologies
advanced
characterization
tools
allow
one
to
correlate
relationships
at
molecular
level.
In
this
Review,
electronic
geometric
structures
single
nanoparticles
will
be
discussed.
Furthermore,
we
summarize
applications
types
reactions,
CO
oxidation,
selective
hydrogenation,
organic
electrocatalytic,
photocatalytic
We
compare
results
obtained
from
systems
try
give
a
picture
how
work
reactions
perspectives
future
directions
toward
better
understanding
entities
unifying
manner.
Chemical Reviews,
Год журнала:
2019,
Номер
120(2), С. 623 - 682
Опубликована: Дек. 23, 2019
The
use
of
well-defined
materials
in
heterogeneous
catalysis
will
open
up
numerous
new
opportunities
for
the
development
advanced
catalysts
to
address
global
challenges
energy
and
environment.
This
review
surveys
roles
nanoparticles
isolated
single
atom
sites
catalytic
reactions.
In
second
section,
effects
size,
shape,
metal-support
interactions
are
discussed
nanostructured
catalysts.
Case
studies
summarized
illustrate
dynamics
structure
evolution
under
certain
reaction
conditions.
third
we
syntheses
applications
atomic
anchored
on
different
types
supports.
final
part,
conclude
by
highlighting
catalyst
gaining
a
fundamental
understanding
their
active
sites.
Angewandte Chemie International Edition,
Год журнала:
2017,
Номер
56(52), С. 16464 - 16483
Опубликована: Июнь 23, 2017
Despite
the
large
number
of
disparate
approaches
for
direct
selective
partial
oxidation
methane,
none
them
has
translated
into
an
industrial
process.
The
methane
to
methanol
is
a
difficult,
but
intriguing
and
rewarding,
task
as
it
potential
eliminate
prevalent
natural
gas
flaring
by
providing
novel
routes
its
valorization.
This
Review
considers
synthesis
derivatives
from
homogeneous
heterogeneous
pathways.
By
establishing
severe
limitations
related
catalytic
we
highlight
vastly
superior
performance
systems
which
produce
or
incorporate
specific
measures,
such
use
multicomponent
catalysts
stabilize
methanol.
We
thereby
identify
protection
being
indispensable
future
research
on
catalysis.
Chemical Reviews,
Год журнала:
2018,
Номер
118(11), С. 5265 - 5329
Опубликована: Май 10, 2018
In
the
past
decade
or
so,
small-pore
zeolites
have
received
greater
attention
than
large-
and
medium-pore
molecular
sieves
that
historically
dominated
literature.
This
is
primarily
due
to
commercialization
of
two
major
catalytic
processes,
NOx
exhaust
removal
methanol
conversion
light
olefins,
take
advantage
properties
these
materials
with
smaller
apertures.
Small-pore
possess
pores
are
constructed
eight
tetrahedral
atoms
(Si4+
Al3+),
each
time
linked
by
a
shared
oxygen
These
eight-member
ring
(8MR)
provide
small
molecules
access
intracrystalline
void
space,
e.g.,
during
car
cleaning
(NOx
removal)
en
route
its
into
while
restricting
larger
molecule
entrance
departure
critical
overall
catalyst
performance.
total,
there
forty-four
structurally
different
zeolites.
Forty-one
can
be
synthesized,
first
synthetic
zeolite
(KFI,
1948)
was
in
fact
material.
Although
field
8MR
chemistry
has
expanded
many
directions,
progress
synthesis
framework-specific,
leaving
insights
generalizations
difficult
realize.
review
focuses
on
relevant
details
all
provides
some
generalized
findings
related
insights.
Next,
applications
where
either
been
commercialized
investigations
presented,
aim
providing
structure-activity
relationships.
The
ends
summary
discusses
(i)
both
progress,
(ii)
list
opportunities
field,
(iii)
brief
future
outlook.
Science,
Год журнала:
2020,
Номер
367(6474), С. 193 - 197
Опубликована: Янв. 10, 2020
Confining
peroxide
to
make
methanol
In
principle,
hydrogen
would
be
an
efficient
oxidant
for
the
conversion
of
methane
under
mild
conditions.
practice,
however,
it
is
currently
too
expensive
produce
ahead
time
this
purpose.
Jin
et
al.
report
a
catalyst
system
that
generates
and
concentrates
immediate
reaction
with
methane.
A
hydrophobically
coated
zeolite
keeps
close
gold
palladium
active
site,
where
incoming
then
selectively
oxidized
methanol.
Science
,
issue
p.
193
Science,
Год журнала:
2017,
Номер
358(6360), С. 223 - 227
Опубликована: Сен. 8, 2017
A
radical
route
from
methane
to
methanol
The
conversion
of
into
chemicals
usually
proceeds
through
high-temperature
routes
that
first
form
more
reactive
carbon
monoxide
and
hydrogen.
Agarwal
et
al.
report
a
low-temperature
(50°C)
in
aqueous
hydrogen
peroxide
(H
2
O
)
for
oxidizing
high
yield
(92%).
They
used
colloidal
gold-palladium
nanoparticles
as
catalyst.
primary
oxidant
was
;
isotopic
labeling
showed
H
activated
methyl
radicals,
which
subsequently
incorporated
.
Science
,
this
issue
p.
223
