PtNiCu nanowires with advantageous lattice–plane boundary for enhanced ethanol electrooxidation

It is generally accepted that the interface effect and surface electronic structure of catalysts have vital impact on catalytic properties. Understanding and tailoring the atomic arrangement of interface structure are of great importance for electrocatalysis. Herein, we proposed a simple method to synthesize etching-PtNiCu nanowires (e-PtNiCu NWs) enclosed by both (110) and (100) facets evolving from PtNiCu nanowires (PtNiCu NWs) mainly with (111) facets by selectively etching process. After acetic acid etching treatment, the e-PtNiCu NWs possess high total proportions (88.3%) of (110) and (100) facets, whereas the (111) facet is dominant in PtNiCu NWs (64%) by qualitatively and quantitatively evaluation. Combining the structure characterizations and performance tests of ethanol electrooxidation reaction (EOR), we find that the e-PtNiCu NWs display remarkably performance for EOR, which is nearly 4.5 times and 1.5 times enhancement compared with the state-of-the-art Pt/C catalyst, as well as 2.2 and 1.4 times of PtNiCu NWs, in specific activity and mass activity, respectively. The improved performance of e-PtNiCu NWs is attributed to synergistic catalytic effect between (110) and (100) facets that not only significantly decreases the onset potentials of adsorbed CO (CO_ads) but also favors the oxidation of CO_ads on the surface of catalyst. Furthermore, thermodynamics and kinetic studies indicate that the synergistic effect of both (110) and (100) facets in e-PtNiCu NWs can decrease the activation energy barrier and facilitate the charge transfer during the reaction. This work provides a promising approach to construct catalysts with tunable surface electronic structure towards efficient electrocatalysis.