IrPd Nanoalloy-Structured Bifunctional Electrocatalyst for Efficient and pH-Universal Water Splitting

The lack of high efficiency and pH-universal bifunctional electrocatalysts for water splitting to hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) hinders the large-scale production of green hydrogen. Here, an IrPd electrocatalyst supported on ketjenblack that exhibits outstanding bifunctional performance for both HER and OER at wide pH conditions is presented. The optimized IrPd catalyst exhibits a specific activity of 4.46 and 3.98 A mg(Ir)(-1) in the overpotential of 100 and 370 mV for HER and OER, respectively, in alkaline conditions. When applied to the anion exchange membrane electrolyzer, the Ir44Pd56/KB catalyst shows a stability of >20 h at a current of 250 mA cm(-2) for water decomposition, indicating promising prospects for practical applications. Beyond offering an advanced electrocatalyst, this work also guides the rational design of desirable bifunctional electrocatalysts for HER and OER by regulating the microenvironments and electronic structures of metal catalytic sites for diverse catalysis.

Automated summary

This study presents an IrPd electrocatalyst supported on ketjenblack that exhibits outstanding bifunctional performance for both HER and OER at wide pH conditions. The optimized IrPd catalyst shows specific activity of 4.46 and 3.98 A mg(Ir)(-1) in the overpotential of 100 and 370 mV for HER and OER, respectively, in alkaline conditions. When applied to the anion exchange membrane electrolyzer, the Ir44Pd56/KB catalyst demonstrates promising prospects for practical applications with stability of >20 h at a current of 250 mA cm(-2) for water decomposition. This work not only offers an advanced electrocatalyst, but also provides guidance for the rational design of desirable bifunctional electrocatalysts for HER and OER by regulating the microenvironments and electronic structures of metal catalytic sites for diverse catalysis.