Highly efficient methanol electrooxidation catalyzed by co-action of PdY2O3 in alkaline solution for fuel cells

Catalytic activity improvement by Pd-based catalyst for methanol oxidation is significant to the development of alkaline direct methanol fuel cells. Herein, we demonstrate the performance of methanol oxidation on Pd catalyst could be greatly increased by Y2O3. The promotion effect is discussed with the help of physical and electrochemical characterization techniques by comparing with a home-made Pd/C catalyst in the identical condition. The presence of Y2O3 in the system is well confirmed by the characteristic peaks indicated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy(XPS); and a strong electronic effect between the Pd and Y2O3 is reflected by an evident shift of binding energy to the lower direction as shown in the XPS spectrum. The catalytic activity expressed by current density reveled by cyclic voltammetry is about 145 mA cm−2, 1.5 times higher than that of the reference catalyst; current retaining ability of 5 times higher than that of the reference catalyst is revealed by Chronoamperometry. Higher catalytic activity and stability for methanol oxidation is discussed due to the relatively well dispersed Pd particle size, increased electroactive surface area and the synergistic interaction of Pd and Y2O3. The work demonstrates the hybrid PdY2O3/C as a newly effective catalyst for alkaline direct methanol fuel cells.