Synthesis of 3D IrRuMn sphere as a superior oxygen evolution electrocatalyst in acidic environment

Designing a 3-dimensional structure for an Ir-based catalysts offers a great opportunity to improved the electrocatalytic execution and maximize the use of precious metal. Here we report a novel wet chemical strategy for synthesizing IrRuMn catalyst with sphere structure and porous feature. In the synthetic process combined use of citric acid and formamide is requisite for the formation of sphere structure. This method leads to a favorable 3D IrRuMn sphere structure with a lot of active sites fully exposed. Furthermore, an alloying noble metal such as Ir and Ru with transition metal demonstrate enhanced OER activity.The doping of transition metal like Mn is an interesting example because it exhibits stability and activity in acidic and alkaline media. For OER, IrRuMn sphere catalyst exhibits overpotential of 260 mV at the current density of 10 mA cm-2 in strong acidic 0.1m HClO4, which are superior to those of commercial IrO2/C catalyst. This approach provides a novel ways to synthesize Ir-based multimetallic sphere electrocatalyst which exhibits exceptional efficient for acidic OER, that will pave new ways in the practical utilization of PEM electrolysers.