Hot-Injection Synthesis of PtCu<sub>3</sub> Concave Nanocubes with High-Index Facets for Electrocatalytic Oxidation of Methanol and Formic Acid

Published on 2020-01-14T22:29:21Z (GMT) by
Extensive 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 PtCu<sub>3</sub> 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 PtCu<sub>3</sub>. The introduction of Br<sup>–</sup> 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 PtCu<sub>3</sub> concave nanocubes exhibit mass activity of 0.69 A mg<sub>Pt</sub><sup>–1</sup> and specific activity of 2.44 mA cm<sub>Pt</sub><sup>–2</sup> 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 mg<sub>Pt</sub><sup>–1</sup> and 1.57 mA cm<sub>Pt</sub><sup>–2</sup>, and are 2.0 and 4.2 times higher than the commercial Pt/C, respectively. The PtCu<sub>3</sub> concave nanocubes and commercial Pt/C show the same onset potentials for methanol oxidation, whereas the onset potential on the PtCu<sub>3</sub> 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 PtCu<sub>3</sub> 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.

Cite this collection

Geng, Jiarun; Zhu, Zhuo; Bai, Xiaoxiao; Li, Fujun; Chen, Jun (2020): Hot-Injection

Synthesis of PtCu3 Concave

Nanocubes with High-Index Facets for Electrocatalytic Oxidation of

Methanol and Formic Acid. ACS Publications. Collection. https://doi.org/10.1021/acsaem.9b02048