Photocatalytic
oxidation
of
methane
(CH4)
to
high
value-added
liquid
oxygenates
with
oxygen
(O2)
as
an
oxidant
has
long
been
a
promising
process.
In
addition
the
activation
CH4,
selective
reduction
O2
hydroperoxyl
(·OOH)
is
also
crucial
factor
in
determining
efficiency
and
selectivity
overall
reaction.
thermal
catalysis,
strong
interactions
between
vacancies
(OVs)
on
catalyst
surface
are
widely
adopted
means
enhancing
activation.
However,
reports
this
phenomenon
limited
photocatalysis;
attributable
fact
that
dependent
upon
its
reaction
photogenerated
electrons
(e-).
For
majority
photocatalysts,
transfer
e-
metal
cocatalysts
results
spatial
separation
from
OVs.
Therefore,
intrinsic
affinity
OVs
not
fully
exploited.
study,
we
discovered
H2
treatment
at
elevated
temperatures
ZIF-8-derived
ZnO
led
formation
OV-enriched
amorphous
layer
surface.
After
introduction
Ag
cocatalyst,
as-prepared
Agx-OVs/ZnO
exhibited
unconventional
carrier
direction,
whereby
holes
(h+)
transferred
Ag,
respectively.
As
result,
preferential
adsorption
sites
can
be
spatially
combined
together
thus
drive
realize
efficient
directed
generation
·OOH.
parallel,
h+
weakens
capability
avoids
overoxidation
while
ensuring
CH4
The
optimized
defect-rich
Ag0.5-OVs/ZnO-z
photocatalyst
reaches
oxygenate
yield
10148
μmol
gcat-1
h-1
95%
TOF
2.4
×
106
gAg-1
h-1.
This
work
sheds
new
light
design
photocatalytic
catalysts
via
manipulation
direction.
Advanced Science,
Journal Year:
2023,
Volume and Issue:
11(8)
Published: Oct. 26, 2023
Methane
as
the
main
component
in
natural
gas
is
a
promising
chemical
raw
material
for
synthesizing
value-added
chemicals,
but
its
harsh
conversion
process
often
causes
severe
energy
and
environment
concerns.
Photocatalysis
provides
an
attractive
path
to
active
convert
methane
into
various
products
under
mild
conditions
with
clean
sustainable
solar
energy,
although
many
challenges
remain
at
present.
In
this
review,
recent
advances
photocatalytic
are
systematically
summarized.
As
basis
of
conversion,
activation
first
elucidated
from
structural
molecules.
The
study
committed
categorizing
elucidating
research
progress
laws
intricate
reactions
according
target
products,
including
partial
oxidation,
reforming,
coupling,
combustion,
functionalization.
Advanced
reactor
designs
also
designed
enrich
options
reliability
performance
evaluation.
prospects
discussed,
which
turn
offers
guidelines
methane-conversion-related
photocatalyst
exploration,
reaction
mechanism
investigation,
advanced
photoreactor
design.
ACS Energy Letters,
Journal Year:
2024,
Volume and Issue:
9(4), P. 1743 - 1752
Published: March 26, 2024
Constructing
vacancy-decorated
heterojunction
photocatalysts
is
a
feasible
strategy
for
highly
efficient
photooxidation
of
toluene
to
benzaldehyde.
However,
poor
interface
interaction
and
vacancy-triggered
mismatched
redox
kinetics
seriously
impede
photocatalytic
activity
improvement.
Herein,
chemically
bonded
Cs3Bi2Br9–x@AgBr
core–shell
with
unified
adsorption-redox
sites
fabricated
via
an
in-situ
light-assisted
Ag+
insertion
method.
Experiments
theoretical
calculations
demonstrate
that
the
type-II
band
alignment
interfacial
Bi–Br–Ag
bonds
boosts
charge
separation.
Moreover,
because
greater
oxygen
adsorption
energy
steric-hindrance
effect
AgBr
shell,
preferred
site
O2
modulated
from
Br
vacancy
(VBr,
trapping
holes)
its
corresponding
reduction
(AgBr,
gathering
electrons),
thereby
ensuring
VBr-enhancing
adsorption/oxidation
on
Cs3Bi2Br9.
Therefore,
exhibits
improved
benzaldehyde
production
rate
5.61
mmol
g–1
h–1
(selectivity:
91%),
outperforming
pure
Cs3Bi2Br9
by
factor
6.
This
work
underlines
importance
rational
design
heterointerface
at
atomic
level
in
photocatalysis.
Science Advances,
Journal Year:
2023,
Volume and Issue:
9(49)
Published: Dec. 8, 2023
Current
chemical
recycling
of
bulk
synthetic
plastic,
polyethylene
(PE),
operates
at
high
temperature/pressure
and
yields
a
complex
mixture
products.
PE
conversion
under
mild
conditions
with
good
selectivity
toward
value-added
chemicals
remains
practical
challenge.
Here,
we
demonstrate
an
atomic
engineering
strategy
to
modify
TiO
2
photocatalyst
reversible
Pd
species
for
the
selective
ethylene
(C
H
4
)
propionic
acid
via
dicarboxylic
intermediates
moderate
conditions.
-supported
atomically
dispersed
exhibits
C
evolution
531.2
μmol
g
cat
−1
hour
,
408
times
that
pristine
.
The
liquid
product
is
valuable
propanoic
98.8%
selectivity.
Plastic
hydrocarbon
yield
0.9%
6.3%
was
achieved
in
oxidation
coupled
3
hours
photoreaction.
In
situ
spectroscopic
studies
confirm
dual
role
species:
electron
acceptor
boost
charge
separation/transfer
efficient
photoredox,
mediator
stabilize
reaction
decarboxylation.
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(23), P. 16039 - 16051
Published: June 4, 2024
Efficient
methane
photooxidation
to
formic
acid
(HCOOH)
has
emerged
as
a
sustainable
approach
simultaneously
generate
value-added
chemicals
and
harness
renewable
energy.
However,
the
persistent
challenge
lies
in
achieving
high
yield
selectivity
for
HCOOH
formation,
primarily
due
complexities
associated
with
modulating
intermediate
conversion
desorption
after
activation.
In
this
study,
we
employ
first-principles
calculations
comprehensive
guiding
tool
discover
that
by
precisely
controlling
O2
activation
process
on
noble
metal
cocatalysts
adsorption
strength
of
carbon-containing
intermediates
oxide
supports,
one
can
finely
tune
products.
Specifically,
bifunctional
catalyst
comprising
Pd
nanoparticles
monoclinic
WO3
(Pd/WO3)
would
possess
optimal
kinetics
an
oxidation/desorption
barrier,
thereby
promoting
formation.
As
evidenced
experiments,
Pd/WO3
achieves
exceptional
4.67
mmol
gcat–1
h–1
62%
under
full-spectrum
light
irradiation
at
room
temperature
using
molecular
O2.
Notably,
these
results
significantly
outperform
state-of-the-art
photocatalytic
systems
operated
identical
condition.
Small,
Journal Year:
2024,
Volume and Issue:
20(28)
Published: Feb. 13, 2024
Abstract
Photocatalytic
oxidative
coupling
of
CH
4
(OCM)
is
a
promising
conversion
process
that
can
achieve
efficient
methane
with
the
assistance
O
2
.
It
remains
to
be
highly
challenging
improve
photocatalytic
OCM
activity
from
catalyst
design
and
deepen
understanding
reactant
activation
in
process.
In
this
work,
Au‐loaded
ZnAl‐layered
double
hydroxides
(LDHs)
without
oxygen
vacancy
are
constructed
(denoted
as
Au/ZnAl
Au/ZnAl‐v),
respectively.
When
applied
for
OCM,
Au/ZnAl‐v
shows
rate
8.5
mmol
g
−1
h
92%
selectivity
C
H
6
at
40
°C,
outperforming
most
reported
systems
low
temperature
literature.
Furthermore,
catalytic
performance
stable
100
h.
contrast,
An/ZnAl
exhibits
0.8
46%
Detailed
characterizations
DFT
calculation
studies
reveal
introduced
Ov
sites
on
able
activate
,
resulting
superoxide
radical
·
−
greatly
promotes
The
3
groups
Au
cocatalyst
leads
formation
high
activity.
ACS Applied Materials & Interfaces,
Journal Year:
2024,
Volume and Issue:
16(4), P. 4600 - 4605
Published: Jan. 19, 2024
Photocatalytic
conversion
of
methane
(CH4)
to
value-added
chemicals
using
H2O
as
the
oxidant
under
mild
conditions
is
a
desired
sustainable
pathway
for
synthesizing
commodity
chemicals.
However,
controlling
product
selectivity
while
maintaining
high
yields
greatly
challenging.
Herein,
we
develop
highly
efficient
strategy,
based
on
precise
control
types
nitrogen
dopants,
and
design
photocatalysts,
achieve
productivity
oxygenates
via
CH4
photocatalytic
conversion.
The
primary
(methanol)
obtained
in
yield
159.8
μmol·g–1·h–1
47.7%
selectivity,
oxygenate
compounds
reached
92.5%.
unique
hollow
porous
structure
substituted
sites
nitrogen-doped
TiO2
synergistically
promote
its
photo-oxidation
performance.
Furthermore,
situ
attenuated
total
reflectance
Fourier
transform
infrared
spectroscopy
provides
direct
evidence
key
intermediates
their
evolution
producing
methanol
multicarbon
oxygenates.
This
study
insights
into
mechanism
Nature Communications,
Journal Year:
2024,
Volume and Issue:
15(1)
Published: Aug. 30, 2024
Direct
methane
conversion
to
high-value
chemicals
under
mild
conditions
is
attractive
yet
challenging
due
the
inertness
of
and
high
reactivity
valuable
products.
This
work
presents
an
efficient
selective
strategy
achieve
direct
through
oxidative
coupling
over
a
visible-responsive
Au-loaded
CeO
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(17), P. 11968 - 11977
Published: April 17, 2024
The
direct
oxidation
of
CH4
to
C2H5OH
is
attractive
but
challenging
owing
the
intricate
processes
involving
carbon-chain
growth
and
hydroxylation
simultaneously.
inherent
difficulty
arises
from
strong
tendency
overoxidize
in
commonly
used
pressurized
powder
suspension
systems
rich
reactive
oxygen
radicals
(ROR),
which
are
specifically
designed
for
concentration
activation.
Meanwhile,
nucleophilic
attack
potent
ROR
on
C–C
bond
resulting
product
ultimately
leads
a
higher
selectivity
C1
oxygenates.
This
study
addresses
this
multifaceted
issue
by
designing
three-phase
interface
based
hydrophilic
floating
Fe(III)-cross-linked
macroporous
alginate
hydrogel
film
encapsulated
with
C3N4
[Fe(III)@ACN]
simultaneously
enhance
accessibility
H2O
molecules
active
sites
species
within
channel.
properties
Fe(III)@ACN
allow
situ
production
H2O2
through
water
reaction
under
irradiation.
concurrent
photoinduced
Fe(II)
triggers
Fenton
produce
•OH.
enhanced
mass
transfer
at
ensures
efficient
formation
•CH3
reacting
•OH,
facilitating
conversion
pathway
CH3OH
finally
•OH
present
comparable
concentrations.
Thus,
catalyst
exhibits
remarkable
96%
alcohol,
achieving
90%
alcohol
products.
rate
reaches
171.7
μmol
g–1
h–1
without
need
precious-metal
additive.