Alloying Pt electrocatalysts with
late transition metals (e.g.,
Ni, Co, and Fe) is an effective strategy to lower the catalyst cost
and improve their tolerance toward CO in the anode of direct ethanol
fuel cells. In this study, shape-controlled octahedral Pt–Ni/C
nanocrystals with uniformly exposed (111) facets and an average edge
length of 10 nm were synthesized. The octahedral Pt–Ni/C nanocatalyst
was at least 4.6 and 7.7 times more active than conventional Pt–Ni/C
and commercial Pt/C catalysts, respectively. In situ infrared spectroscopic
results showed that the acetic acid/CO2 absorbance peak
intensity on octahedral Pt–Ni/C was 7.6 and 1.4 times higher
as compared to commercial Pt/C and conventional Pt–Ni/C, respectively,
at 0.75 V. This result suggests that ethanol oxidation on octahedral
Pt–Ni produces more acetic acid than on other surfaces. The
synergistic electronic and facet effects may explain the superior
ethanol oxidation reaction activity of octahedral Pt–Ni/C.
Further surface modification with Ru significantly lowered the onset
potential for CO2 production by ∼100 mV and resulted
in a higher selectivity on CO2 as compared to unmodified
surface, which further boosted the ethanol utilization efficiency.
The anodic reaction in direct ethanol fuel cells (DEFCs), ethanol oxidation reaction (EOR) faces challenges, such as incomplete electrooxidation of ethanol and high cost of the most efficient electrocatalyst, Pt in acidic media at low temperature. In this study, core‐shell electrocatalysts with an Au core and Pt‐based shell (Au@Pt) are developed. The Au core size and Pt shell thickness play an important role in the EOR activity. The Au size of 2.8 nm and one layer of Pt provide the most optimized performance, having 6 times higher peak current density in contrast to commercial Pt/C. SnO2 as a support also enhances the EOR activity of Au@Pt by 1.73 times. Further modifying the Pt shell with Ru atoms achieve the highest EOR current density that is 15 and 2.5 times of Pt/C and Au@Pt. Our results suggest the importance of surface modification in rational design of advanced electrocatalysts.
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.