| Summary: | The compositions and surface facets of platinum (Pt)-based electrocatalysts are of great significance for the development of direct alcohol fuel cells (DAFCs). We reported an approach for preparing ultrathin Pt<sub>n</sub>Co<sub>100−n</sub> nanowire (NW) catalysts with high activity. The Pt<sub>n</sub>Co<sub>100−<i>n</i></sub> NW alloy catalysts synthesized by single-phase surfactant-free synthesis have adjustable compositions and (111) plane and strain lattices. X-ray diffraction (XRD) results indicate that the alloy composition can adjust the lattice shrinkage or expansion of Pt<sub>n</sub>Co<sub>100−n</sub> NWs. X-ray photoelectron spectroscopy (XPS) results show that the electron structure of Pt is changed by the alloying effect caused by electron modulation in the d band, and the chemical adsorption strength of Pt is decreased, thus the catalytic activity of Pt is increased. The experimental results show that the activity of Pt<sub>n</sub>Co<sub>100−n</sub> for the oxidation of methanol and ethanol is related to the exposed crystal surface, strain lattice and composition of catalysts. The Pt<sub>n</sub>Co<sub>100−n</sub> NWs exhibit stronger electrocatalytic performance for both methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR). The dominant (111) plane Pt<sub>53</sub>Co<sub>47</sub> exhibits the highest electrocatalytic activity in MOR, which is supported by the results of XPS. This discovery provides a new pathway to design high activity, stability nanocatalysts to enhance direct alcohol fuel cells.
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