Electrocatalytic activity of multi-walled carbon nanotubes-supported PtxPdy catalysts prepared by a pyrolysis process toward ethanol oxidation reaction

• Multi-walled carbon nanotubes nanocomposite catalysts decorated with PtxPdy nanoparticles were prepared by a simple pyrolysis process.
• PtxPdy nanoparticles with an average particle size of ~4.0 nm were quite uniformly dispersed on the surface of MWCNTs.
• The onset potential is found to be ~200 mV lower and the peak current is 10 times higher for EOR with Pt3Pd3/MWCNTs catalysts relative to Pt/MWCNTs catalysts.

Multi-walled carbon nanotubes (MWCNTs)-supported Pt–Pd bimetallic nanoparticles with various feed molar ratios (denoted as PtxPdy/MWCNTs) are successfully prepared for the first time by a simple method of pyrolysis without any additional reducing agent. The obtained PtxPdy/MWCNTs catalysts are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Results show that PtxPdy particles with an average particle size of ~4.0 nm are dispersed quite uniformly on the surface of MWCNTs. The electrocatalytic activity of the PtxPdy/MWCNTs catalysts toward ethanol oxidation reaction (EOR) is examined by cyclic voltammetry (CV) in basic solution. Surprisingly, significantly enhanced EOR peak currents are observed under the catalysis of Pt3Pd3/MWCNTs, where the feed molar ratio of Pt to Pd is 3:3. The onset potential is found to be ~200 mV lower and the peak current is 10 times higher for the ethanol oxidation with Pt3Pd3/MWCNTs catalysts when compared to the ethanol oxidation with Pt/MWCNTs catalysts. The existence of PdO is considered as the possible reason for the remarkably enhanced peak currents of EOR in the presence of Pt3Pd3/MWCNTs catalysts.

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