Electrochemical Science Advances,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Dec. 25, 2024
ABSTRACT
Oxygen
reduction
reaction
(ORR)
is
key
in
many
green
energy
conversion
devices
like
fuel
cells
and
metal‐air
batteries.
Developing
cheap
robust
electrocatalysts
crucial
to
expedite
the
slow
ORR
kinetics
at
cathode.
Lately,
transition
metal
(TM)
heteroatom‐doped
carbon
catalysts
have
surfaced
as
promising
cathode
materials
for
they
display
admirable
electrocatalytic
activity
distinguished
properties
tunable
morphology,
structure,
composition
porosity.
This
review
summarizes
recent
breakthrough
TM
(Fe,
Co,
Mn
Ni)
heteroatoms
(N,
S,
B,
P
F)
doping
materials.
Moreover,
their
active
sites
are
inspected
future
augmentation
making
electrochemical
devices.
The
existing
challenges
prospects
this
field
ratiocinated
conclusion.
It
is
challenging
to
selectively
promote
the
two-electron
oxygen
reduction
reaction
(2e-ORR)
since
highly
ORR-active
electrocatalysts
are
not
satisfied
with
2e-ORR
and
most
likely
go
all
way
4e-ORR,
completely
reducing
dioxygen
water.
Recently,
however,
possibility
of
a
preference
over
4e-ORR
was
raised
by
extensively
considering
multiple
ORR
mechanisms
employing
potential-dependent
activity
measure
for
constructing
volcano
plots.
Here,
we
realized
preferred
via
an
intramolecular
double
activation
peroxide
intermediate
(*OOH)
allowing
be
easily
desorbed
before
proceeding
4e-ORR.
Dioxygen
transformed
*OOH
on
carbon
atom
imidazole
ligand
zeolitic
imidazolate
framework-8
(ZIF-8).
When
amine
group
introduced
exchange,
selectivity
enhanced
11%.
The
added
attracted
hydrogen
bond
weaken
binding
strength
active
site
(double
activation).
amine-decorated
ZIF-8
exhibited
H2O2
faradaic
efficiency
at
98.5%
ultrahigh-rate
production
625
mg
cm–2
h–1
1
A
in
flow
cell.
ChemSusChem,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Aug. 26, 2024
Abstract
Platinum
group
metal
(PGM)‐free
electrocatalysts
have
emerged
as
promising
alternatives
to
replace
Pt
for
the
oxygen
reduction
reaction
(ORR)
in
anion
exchange
membrane
fuel
cells
(AEMFCs).
However,
traditional
synthesis
methods
limit
single‐atom
site
density
due
agglomeration
at
higher
temperatures.
This
work
explores
preparation
of
hierarchically
porous
atomically
dispersed
ORR.
The
materials
were
prepared
via
ionothermal
synthesis,
where
magnesium
nitrate
was
used
prepare
carbon
materials.
in‐situ
formed
Mg‐N
x
sites
trans‐metalated
yield
ORR‐active
Fe‐N
sites.
resulting
carbon‐based
catalysts
displayed
excellent
electrocatalytic
activity,
attributed
active
and
high
meso‐
macroporosity
that
enhanced
mass
transport
exposed
more
accessible
