Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(52)
Published: Nov. 18, 2024
Abstract
The
active
sites
of
metalloenzymes
involved
in
small
molecules
activation
often
contain
pendant
bases
that
act
as
proton
relay
promoting
proton‐coupled
electron‐transfer
processes.
Here
we
focus
on
hydrogenases
and
the
reactions
they
catalyze,
i.
e.
hydrogen
evolution
oxidation
reactions.
After
a
short
description
these
enzymes,
review
some
various
biomimetic
bioinspired
molecular
systems
relays.
We
then
provide
formal
electrochemical
framework
required
to
decipher
key
role
such
enhance
catalysis
single
direction
discuss
few
for
H
2
which
quantitative
kinetic
data
are
available.
finally
highlight
parameters
reach
bidirectional
(both
catalyzed)
transition
reversible
catalyzed
narrow
potential
range)
well
illustrate
features
from
literature.
Inorganic Chemistry,
Journal Year:
2024,
Volume and Issue:
63(26), P. 12133 - 12145
Published: June 20, 2024
The
1,2-insertion
reaction
of
CO2
into
metal–hydride
bonds
d6-octahedral
complexes
to
give
κ1-O-metal-formate
products
is
the
key
step
in
various
reduction
schemes
and
as
a
result
has
attracted
extensive
mechanistic
investigations.
For
many
octahedral
catalysts,
insertion
follows
an
associative
mechanism
which
interacts
directly
with
coordinated
hydride
ligand
instead
more
classical
dissociative
that
opens
empty
coordination
site
bind
substrate
metal
prior
migration
step.
To
better
understand
mechanism,
we
conducted
systematic
quantum
chemical
investigation
on
between
fac-(bpy)Re(CO)3H
(1–Re–H;
bpy
=
2,2′-bipyridine)
starting
gas
phase
then
moving
THF
other
solvents
increased
dielectric
constants.
Detailed
analyses
potential
energy
surfaces
(PESs)
intrinsic
coordinates
(IRCs)
reveal
enabled
all
media
by
initial
stage
making
3c-2e
bond
carbon
metal-hydride
most
consistent
organometallic
bridging
Re–H–CO2
species.
Once
bent
anchored
bond,
proceeds
rotation
motion
via
cyclic
transition
state
TS2
interchanges
Re–O–CHO
coordination.
combined
stages
provide
asynchronous–concerted
pathway
for
Gibbs
free
surface
highest
point.
Consideration
rate-determining
TS
gives
activation
barriers,
inverse
KIEs,
substituent
effects,
solvent
effects
agree
experimental
data
available
this
system.
An
important
new
insight
revealed
results
not
transfer
been
assumed
some
studies.
In
fact,
loose
vibration
can
be
identified
first
solution
(TS1)
does
involve
Re–H
stretching
vibrational
mode.
Accordingly,
imaginary
frequency
TS1
insensitive
deuteration,
therefore,
leads
no
significant
KIE.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(13)
Published: Feb. 7, 2024
Abstract
The
electronic
structure
of
metal
complexes
plays
key
roles
in
determining
their
catalytic
features.
However,
controlling
structures
to
regulate
reaction
mechanisms
is
fundamental
interest
but
has
been
rarely
presented.
Herein,
we
report
tuning
Cu
porphyrins
switch
pathways
the
hydrogen
evolution
(HER).
Through
controllable
and
regioselective
β
‐oxidation
porphyrin
1
,
synthesized
analogues
2–4
with
one
or
two
‐lactone
groups
either
a
cis
trans
configuration.
Complexes
1–4
have
same
Cu‐N
4
core
site
different
structures.
Although
led
large
anodic
shifts
reductions,
displayed
similar
HER
activities
terms
close
overpotentials.
With
electrochemical,
chemical
theoretical
results,
show
that
catalytically
active
species
switches
from
I
for
0
.
This
work
thus
significant
present
mechanism‐controllable
via
catalysts.
Deleted Journal,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 3, 2024
Renewable
electrical
energy
for
electrolysis
water
can
achieve
green
industrial
chains
hydrogen
production.
However,
finding
efficient
electrocatalysts
remains
a
challenge
hydrogen.
Herein,
sub-nanometric
FeCoP
nanosheets
with
average
thickness
of
0.9
nm
is
constructed
through
2D
self-assembly
driven
by
cavitation
effect
ultrasonics
and
following
phosphating.
Benefiting
from
abundant
active
sites,
enhanced
H2O
molecular
adsorption
kinetics,
highly
structural
stability,
the
subcrystalline
shows
excellent
electrocatalytic
activities
evolution
reaction
(HER)
oxygen
reactions
(OER).
Ultralow
overpotential
37
mV
achieved
at
10
mA·cm−2
HER.
When
catalyst
was
used
as
both
cathode
anode
overall
splitting
using
renewable
energy,
produced
directly
applied
fuel
cell
to
drive
fan
more
than
h.
Theoretical
calculation
indicates
that
easily
adsorbs
crystalline
one
thus
speeds
up
kinetics
Volmer
step
in
HER
process.
Angewandte Chemie,
Journal Year:
2024,
Volume and Issue:
136(47)
Published: Aug. 15, 2024
Abstract
Improving
proton
transfer
is
vital
for
electrocatalysis
with
porous
materials.
Although
several
strategies
are
reported
to
assist
in
channels,
few
studies
dedicated
improving
at
the
local
environments
of
active
sites
Herein,
we
report
on
new
Co‐corrole‐based
organic
polymers
(POPs)
improved
electrocatalytic
oxygen
reduction
reaction
(ORR)
and
evolution
(OER).
By
tuning
pore
sizes
installing
relays
Co
corrole
sites,
designed
synthesized
POP‐2‐OH
both
channels
sites.
This
POP
shows
remarkable
activity
ORR
E
1/2
=0.91
V
vs
RHE
OER
η
10
=255
mV.
Therefore,
this
work
significant
present
a
strategy
improve
site
materials
highlight
key
role
such
structural
functionalization
boosting
electrocatalysis.
Angewandte Chemie International Edition,
Journal Year:
2024,
Volume and Issue:
63(52)
Published: Nov. 18, 2024
Abstract
The
active
sites
of
metalloenzymes
involved
in
small
molecules
activation
often
contain
pendant
bases
that
act
as
proton
relay
promoting
proton‐coupled
electron‐transfer
processes.
Here
we
focus
on
hydrogenases
and
the
reactions
they
catalyze,
i.
e.
hydrogen
evolution
oxidation
reactions.
After
a
short
description
these
enzymes,
review
some
various
biomimetic
bioinspired
molecular
systems
relays.
We
then
provide
formal
electrochemical
framework
required
to
decipher
key
role
such
enhance
catalysis
single
direction
discuss
few
for
H
2
which
quantitative
kinetic
data
are
available.
finally
highlight
parameters
reach
bidirectional
(both
catalyzed)
transition
reversible
catalyzed
narrow
potential
range)
well
illustrate
features
from
literature.
Dalton Transactions,
Journal Year:
2024,
Volume and Issue:
53(48), P. 19121 - 19125
Published: Jan. 1, 2024
A
Cu
porphyrin
bearing
four
meso
-CF
3
substituents
is
synthesized
and
displays
higher
activity
than
reported
porphyrins
for
the
electrocatalytic
hydrogen
evolution
reaction.
Electrocatalytic
reduction
of
CO2
into
value-added
chemicals
has
been
considered
as
a
promising
pathway
to
alleviate
the
energy
crisis
and
global
warming.
Iron
porphyrins
have
extensively
studied
for
electrocatalytic
reaction
(CO2RR)
are
well
documented
promote
CO2-to-CO
conversion.
However,
mechanism
CO2-to-HCOO-
conversion
by
Fe
porphyrin
remains
unclear.
Here,
means
density
functional
theory
(DFT)
calculations,
we
investigated
detailed
novel
catalyst
HCOO-
in
its
Fe(I)
state.
Our
results
demonstrated
that
proceeds
through
C-protonation
an
FeII-OCO·-
complex
rather
than
hydrolysis
FeIII-COOH
or
insertion
Fe-H
bond.
Moreover,
is
not
stable
intermediate.
The
protonation
hydroxyl
group
with
concomitant
C-OH
bond
cleavage
produce
CO
thermodynamically
kinetically
unfeasible.
Instead,
can
undergo
coordination
switch
followed
conformational
change
form
active
production
HCOO-.
single-electron
gives
FeII-COOH,
which
leads
formation
insights
gained
from
this
work
may
be
useful
designing
electrocatalysts
selective
formate.
ACS electrochemistry.,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 13, 2024
An
alkyne-terminated
cobalt
complex,
[Co(Cp)(dppe≡H)(Cl)]+
(Cp
=
cyclopentadienyl;
dppe≡H
1,2-bis-(di-(4-ethynyl-phenyl)phosphino)ethane),
(Co≡H)
was
immobilized
onto
a
glassy
carbon
electrode
using
two
attachment
strategies:
Cu(I)
catalyzed
azide–alkyne
click
chemistry
and
reductive
electropolymerization.
The
modified
electrodes
prepared
through
electropolymerization
exhibit
current
densities
peak
resolutions
for
the
electrochemical
reduction
of
species,
which
are
amenable
to
electroanalytical
quantification
coupled
chemical
reactions.
Through
shift
analysis
cyclic
voltammograms
recorded
in
presence
4-chloroanilinium
tetrafluoroborate,
we
quantified
proton
transfer
rate
constant
stepwise
proton-coupled
electron
reaction
that
reduces
electrode-immobilized
[H–Co(Cp)(dppe≡H)]+
(kPTapp
(9.3
±
1.8)
×
105
M–1
s–1).
extraction
kinetic
parameters
an
elementary
complex
represents
first
experimental
measurement
its
type
lays
crucial
groundwork
analyses
hybrid
catalyst–electrode
architectures.