Journal of the American Chemical Society,
Год журнала:
2022,
Номер
145(3), С. 1497 - 1504
Опубликована: Дек. 13, 2022
A
coordination-induced
trigger
for
catalytic
activity
is
proposed
on
an
N-heterocyclic
carbene
(NHC)-decorated
ceria
catalyst
incorporating
Cr
and
Rh
(ICy-r-Cr0.19Rh0.06CeOz).
ICy-r-Cr0.19Rh0.06CeOz
was
prepared
by
grafting
1,3-dicyclohexylimidazol-2-ylidene
(ICy)
onto
H2-reduced
Cr0.19Rh0.06CeOz
(r-Cr0.19Rh0.06CeOz)
surfaces,
which
went
to
exhibit
substantial
the
1,4-arylation
of
cyclohexenone
with
phenylboronic
acid,
whereas
r-Cr0.19Rh0.06CeOz
without
ICy
inactive.
FT-IR,
K-edge
XAFS,
XPS,
photoluminescence
spectroscopy
showed
that
carbene-coordinated
nanoclusters
were
key
active
species.
The
ICy-bearing
could
not
be
attributed
electronic
donation
from
nanoclusters.
DFT
calculations
suggested
controlled
adsorption
sites
phenyl
group
nanocluster
promote
C-C
bond
formation
cyclohexenone.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(48)
Опубликована: Авг. 13, 2024
Abstract
Covalent
organic
frameworks
(COFs)
have
been
demonstrated
as
promising
photocatalysts
for
hydrogen
peroxide
(H
2
O
)
production.
However,
the
construction
of
COFs
with
new
active
sites,
high
photoactivity,
and
wide‐range
light
absorption
efficient
H
production
remains
challenging.
Herein,
we
present
synthesis
a
novel
azobenzene‐bridged
2D
COF
(COF‐TPT‐Azo)
excellent
performance
on
photocatalytic
under
alkaline
conditions.
Notably,
although
COF‐TPT‐Azo
differs
by
only
one
atom
(−N=N−
vs.
−C=N−)
from
its
corresponding
imine‐linked
counterpart
(COF‐TPT‐TPA),
exhibits
significantly
narrower
band
gap,
enhanced
charge
transport,
prompted
photoactivity.
Remarkably,
when
employed
metal‐free
photocatalyst,
achieves
rate
up
to
1498
μmol
g
−1
h
at
pH
=
11,
which
is
7.9
times
higher
than
that
COF‐TPT‐TPA.
Further
density
functional
theory
(DFT)
calculations
reveal
−N=N−
linkages
are
sites
photocatalysis.
This
work
provides
prospects
developing
high‐performance
COF‐based
photocatalysts.
Industrial Chemistry and Materials,
Год журнала:
2023,
Номер
2(1), С. 7 - 29
Опубликована: Июль 20, 2023
In
this
work,
the
theoretical
basis,
catalyst
design
and
in
situ
application
of
DSHP
are
comprehensively
summarized.
It
has
certain
guiding
significance
for
future
catalysts.
Angewandte Chemie International Edition,
Год журнала:
2024,
Номер
63(27)
Опубликована: Апрель 4, 2024
The
formation
of
transient
hybrid
nanoscale
metal
species
from
homogeneous
molecular
precatalysts
has
been
demonstrated
by
in
situ
NMR
studies
catalytic
reactions
involving
transition
metals
with
N-heterocyclic
carbene
ligands
(M/NHC).
These
structures
provide
benefits
both
complexes
and
nanoparticles,
enhancing
the
activity,
selectivity,
flexibility,
regulation
active
species.
However,
they
are
challenging
to
identify
experimentally
due
unsuitability
standard
methods
used
for
or
heterogeneous
catalysis.
Utilizing
a
sophisticated
solid-state
technique,
we
evidence
NHC-ligated
catalytically
Pd
nanoparticles
(PdNPs)
Pd/NHC
during
coordination
NHCs
via
C
Langmuir,
Год журнала:
2024,
Номер
40(19), С. 10374 - 10383
Опубликована: Май 3, 2024
N-Heterocyclic
carbene
(NHC)
ligands
have
been
self-assembled
on
various
metal
and
semimetal
surfaces,
creating
a
covalent
bond
with
surface
atoms
that
led
to
high
thermal
chemical
stability
of
the
monolayer.
This
study
explores
self-assembly
NHCs
metal-oxide
films
(CuOx,
FeOx,
TiOx)
reveals
properties
these
substrates
play
pivotal
role
in
dictating
adsorption
behavior
NHCs,
influencing
decomposition
route
monolayer
its
impact
work
function
values.
While
attachment
onto
CuOx
is
via
coordination
oxygen
atoms,
interact
TiOx
through
FeOx
both
atoms.
These
distinct
binding
modes
arise
due
variances
electronic
within
investigated
films.
Contact
angle
ultraviolet
photoelectron
spectroscopy
measurements
shown
significantly
higher
F-NHC
than
,
correlated
preferred,
averaged
upright
orientation
CuOx.
