PEDOT-embellished Ti3C2Tx nanosheet supported Pt–Pd bimetallic nanoparticles as efficient and stable methanol oxidation electrocatalysts

Abstract

Exploiting high-efficiency and durable electrocatalysts toward the methanol oxidation reaction (MOR) is crucial for the advancement of direct methanol fuel cells (DMFCs). Herein, we demonstrate the loading of platinum–palladium bimetallic nanoparticles (Pt–Pd NPs) onto poly(3,4-ethylenedioxythiophene) (PEDOT)-embellished titanium carbide (Ti₃C₂Tx) nanosheets as the electrocatalyst (Ti₃C₂Tx/PEDOT/Pt–Pd) via a facile and rapid chemical reduction-assisted one-pot hydrothermal process. The structural and morphological analyses of Ti₃C₂Tx/PEDOT/Pt–Pd indicate that the three-dimensional (3D) hybrid structure formed between PEDOT and Ti₃C₂Tx provides a sizable active surface and more active sites, which enhances the homogeneous dispersion of the Pt–Pd NPs and facilitates mass transfer. The Schottky junctions formed between PEDOT and Pt–Pd NPs contribute to charge transfer. The electronic effects and synergistic interactions between the support and catalyst favor the electrocatalytic activity of the catalyst. The electrochemical test results reveal that the Ti₃C₂Tx/PEDOT/Pt–Pd catalyst has prominent electrocatalytic capability for the MOR. Compared with Ti₃C₂Tx/Pt–Pd and commercial Pt/C catalysts, the Ti₃C₂Tx/PEDOT/Pt–Pd catalyst has a larger electrochemical activity surface area (ECSA = 122 m² g⁻¹) and higher mass activity (MA = 1445.4 mA mg⁻¹), as well as better CO tolerance and more reliable long-term durability (a peak current density retention of 71% after 5200 s).