Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
181885 | Electrochemistry Communications | 2007 | 6 Pages |
Platinum nanoparticles were deposited on the surface of IrO2 by chemical reduction. The morphology and structure of nanostructural Pt/IrO2 composites were characterized by XRD, EDX and FE-SEM. The reduction of PtCl62- ions in sodium borohydride aqueous solution containing sodium dodecylbenzenesulfonate (SDBS) additive leads to a fine dispersion and high loading of platinum nanoparticles on IrO2 without serious aggregation. A slight up-shift of the 2θ values in XRD patterns indicates some interaction between IrO2 and Pt nanoparticles in the sizes of ca. 10–20 nm. As bifunctional electrocatalyst for oxygen electrode, IrO2-supported Pt exhibits slightly lower oxygen reduction reaction (ORR) activity but markedly higher oxygen evolution reaction (OER) activity than a mixture of Pt and IrO2. It could be explained by the downshift of the d-band center (∈d) through the d-band coupling model and resulting weak O2 molecule adsorption on Pt catalysts supported by IrO2.