Stereo Assembly of Bimetallic PtPd on Ti3C2Tx/PProDOT for Efficient Methanol Oxidation Reaction in Both Acidic and Alkaline Media

Abstract

The rational construction of efficient and stable electrocatalysts for methanol oxidation reaction (MOR) in acidic and alkaline media affects the commercialization of direct methanol fuel cells (DMFCs). Here, poly(3,4-propylenedioxythiophene) (PProDOT)-embedded Ti₃C₂T_x flakes for the growth of platinum and palladium bimetallic nanoparticles (PtPd) by a chemically reduced hydrothermal process are assembled. The constructed Ti₃C₂T_x/PProDOT/PtPd hybrids exhibit 3D-layered stereoscopic structures. After the embedding of PProDOT, the re-stacking of MXene flakes is suppressed and the interlayer spacing between flakes is extended, allowing the Ti₃C₂T_x/PProDOT interface to promote nanoparticle deposition, active site exposure, and charge transport. The electrochemical test outcomes reveal that the catalytic activity of Ti₃C₂T_x/PProDOT/PtPd for MOR far exceeds that of Ti₃C₂T_x/PtPd and Pt/C. In acidic electrolytes, the mass activity (MA) of Ti₃C₂T_x/PProDOT/PtPd is 2206.1 mA mg⁻¹, which is 4.4 and 5.8 times higher than that of Ti₃C₂T_x/PtPd and Pt/C, respectively. In alkaline electrolytes, the MA of Ti₃C₂T_x/PProDOT/PtPd reaches 4180 mA mg⁻¹, which is 2.1 and 4.8 times higher than that of Ti₃C₂T_x/PtPd and Pt/C, respectively. Meanwhile, its stability and CO tolerance improve significantly. Besides, Ti₃C₂T_x/PProDOT/PtPd also exhibits enhanced catalytic activity toward ethanol oxidation.