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Hot-Injection Synthesis of PtCu3 Concave Nanocubes with High-Index Facets for Electrocatalytic Oxidation of Methanol and Formic Acid
journal contribution
posted on 2020-01-14, 22:29 authored by Jiarun Geng, Zhuo Zhu, Xiaoxiao Bai, Fujun Li, Jun ChenExtensive
efforts have been devoted to tailoring the composition
and shape of Pt nanomaterials for a high catalytic property. Herein,
we report facile hot-injection synthesis of PtCu3 concave
nanocubes enclosed by high-index facets of {720}, {520}, and {320}.
Cetyltrimethylammonium bromide (CTAB) and trinoctylphospine oxide
(TOPO), as the structural-directing agents, play indispensable roles
in the formation of concave nanocubes of PtCu3. The introduction
of Br– from CTAB facilitates the galvanic replacement
reaction on the {100} facets, which lead to formation of the concave
structure; TOPO is essential to achieve the uniform cubic structure.
The PtCu3 concave nanocubes exhibit mass activity of 0.69
A mgPt–1 and specific activity of 2.44
mA cmPt–2 for methanol oxidation, which
are 2.1 and 4.4 times higher than the commercial Pt/C, respectively;
for formic acid oxidation they are 0.45 A mgPt–1 and 1.57 mA cmPt–2, and are 2.0 and
4.2 times higher than the commercial Pt/C, respectively. The PtCu3 concave nanocubes and commercial Pt/C show the same onset
potentials for methanol oxidation, whereas the onset potential on
the PtCu3 concave nanocubes for formic acid oxidation is
negatively shifted by ca. 124 mV compared to that of the commercial
Pt/C. It suggests that the PtCu3 concave nanocubes are
more sensitive to the electrocatalytic oxidation of formic acid than
methanol. This superior electrochemical performance will inspire more
investigations into the rational design of high-performance Pt-based
electrocatalysts.