A Facile Route to Fabricate Effective Pt/IrO2 Bifunctional Catalyst for Unitized Regenerative Fuel Cell

In order to fabricate effective bifunctional oxygen catalyst, IrO 2 nanoparticles have been synthesized by hydrothermal method, and Pt/IrO 2 bifunctional catalyst is then prepared by a microwave-assisted polyol process. X-ray diffraction and transmission electron microscopy are employed to characterize the catalysts, which reveal that Pt with a particle size of 2–3 nm is deposited on IrO 2 surface. Electrochemical tests indicate that Pt/IrO 2 bifunctional catalyst possesses much higher catalytic activity and durability towards both oxygen reduction reaction and oxygen evolution reaction than pure Pt or pure IrO 2 . Kinetic analysis shows that the oxygen reduction reaction on Pt/IrO 2 catalyst mainly follows four-electron pathway. Graphical Abstract Ultrafine Pt particles (2–3 nm) are supported on the surface of amorphous IrO 2 to form Pt/IrO 2 bifunctional catalyst that possesses higher catalytic activities towards both OER and ORR.