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

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 Ti3C2Tx flakes for the growth of platinum and palladium bimetallic nanoparticles (PtPd) by a chemically reduced hydrothermal process are assembled. The constructed Ti3C2Tx/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 Ti3C2Tx/PProDOT interface to promote nanoparticle deposition, active site exposure, and charge transport. The electrochemical test outcomes reveal that the catalytic activity of Ti3C2Tx/PProDOT/PtPd for MOR far exceeds that of Ti3C2Tx/PtPd and Pt/C. In acidic electrolytes, the mass activity (MA) of Ti3C2Tx/PProDOT/PtPd is 2206.1 mA mg-1, which is 4.4 and 5.8 times higher than that of Ti3C2Tx/PtPd and Pt/C, respectively. In alkaline electrolytes, the MA of Ti3C2Tx/PProDOT/PtPd reaches 4180 mA mg-1, which is 2.1 and 4.8 times higher than that of Ti3C2Tx/PtPd and Pt/C, respectively. Meanwhile, its stability and CO tolerance improve significantly. Besides, Ti3C2Tx/PProDOT/PtPd also exhibits enhanced catalytic activity toward ethanol oxidation.