Hierarchical
porous carbon-encapsulated ultrasmall PtCu (UsPtCu@C)
nanoparticles (NPs) were constructed based on segmentation and re-encapsulation
of porous PtCu NPs by using glucose as a green biomass carbon source.
The synergistic electronic effect from the bimetallic elements can
enhance the catalytic activity by adjusting the surface electronic
structure of Pt. Most importantly, the generated porous carbon shell
provided a large contact surface area, excellent electrical conductivity,
and structural stability, and the ultrasmall PtCu NPs exhibited an
increased electrochemical performance compared with their PtCu matrix
because of the exposure of more catalytically active centers. This
synergistic relationship between the components resulted in enhanced
catalytic activity and better stability of the obtained UsPtCu@C for
ethylene glycol oxidation reaction and the oxygen-reduction reaction
in alkaline electrolyte, which was higher than the PtCu NPs and commercial
Pt/C (20 wt % Pt on Vulcan XC-72). The electrochemically active surface
areas of the UsPtCu@C, PtCu NPs, and commercial Pt/C were calculated
to be approximately 230.2, 32.8, and 64.0 m2/gPt, respectively; the mass activity of the UsPtCu@C for the ethylene
glycol oxidation reaction was 8.5 A/mgPt, which was 14.2
and 8.5 times that of PtCu NPs and commercial Pt/C, respectively.
The specific activity of UsPtCu@C was 3.7 mA/cmpt
2, which was 2.1 and 2.3 times
that of PtCu NPs and commercial Pt/C, respectively. The onset potential
(E
on‑set) of UsPtCu@C for the oxygen-reduction
reaction was 0.96 V (vs reversible hydrogen electrode, RHE), which
was 110 and 60 mV higher than PtCu and commercial Pt/C, respectively.
The half-wave potentials (E
1/2) of UsPtCu@C,
PtCu, and Pt/C were 0.88, 0.56, and 0.82 V (vs RHE), respectively,
which indicated that the UsPtCu@C catalyst had an excellent bifunctional
electrocatalytic activity.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.