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Chen et al. Energy Mater 2022;2:200033 https://dx.doi.org/10.20517/energymater.2022.36 Page 9 of 11

Table 1. Comparison of electrochemical catalysis
ECSA (m /g) MA (mA/mg ) Half-wave potential (V)
2
Samples Pt
Initial After ADT Loss Initial After ADT Loss Initial After ADT Loss
PtCu aerogels/C 43.6 34.0 22.1% 369.4 213.7 42.3% 0.926 0.906 0.020
Pt/C 54.3 47.1 13.4% 140.0 105.0 25.0% 0.885 0.873 0.012

Figure 7. Structural characterization of PtCu aerogels/C obtained after ADT. (A, B) HRTEM images and (C) HAADF-STEM and EDX
mapping images.

We considered that the enhanced ORR activity of the PtCu aerogels may originate from two aspects. For the
topological structure of the PtCu aerogels, the high specific area provided more active sites and the larger
porosity helped improve the mass transfer. For the crystal structure of the PtCu alloy, alloying with Cu
lowers the d-band center of Pt and consequently weakens the oxygen adsorption energy of Pt, helping
[1]
increase the activity . Furthermore, the PtCu exposed mainly (111) facets, which is the best facet for
catalyzing ORR . As a result, the PtCu aerogels exhibited excellent electrochemical catalysis towards the
[36]
ORR.

CONCLUSIONS
In conclusion, PtCu aerogels were successfully synthesized by a facile NaBH reduction reaction and showed
4
a porous structure with high specific surface areas. The synthesis period was effectively reduced from tens of
hours to tens of minutes. By controlling the addition of citrate, we discussed that the gelation of PtCu
followed the rapid nucleation mechanism. Moreover, the as-prepared PtCu aerogels exposed mainly the
most active facets for the ORR and consequently exhibited a remarkable ORR performance compared to
Pt/C. This facile route and good catalytic activity may help develop efficient catalysts for fuel cell
applications.

DECLARATIONS
Authors’ contributions
Experiments, data analysis and manuscript writing: Chen Z
Assistance in experiments and data analysis: Liao Y
Supervision of the research: Chen S

Availability of data and materials
Not applicable.