Polydopamine and NaCl template approach to develop a microporous RuO2@IrOx Core–Shell catalyst for an efficient oxygen evolution reaction in polymer electrolyte membrane water electrolyzers

Abstract

To obtain a stable and active catalyst for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolysis (PEMWE), a microporous RuO₂@IrO_x core–shell was synthesized using a polydopamine (PDA) coating and a NaCl filler method. A durable IrO_x shell was homogeneously formed on the surface of the RuO₂ core via impregnation of the PDA coating, which improved the catalytic stability. The NaCl filler created micropores within the nanostructures, increasing the number of active catalytic sites. The strong interaction between the RuO₂ core and protective IrO_x shell, along with the micropores, significantly improved OER activity, showing an overpotential of 182 mV at 10 mA cm⁻². Furthermore, a PEMWE exhibited excellent performance, achieving a current density of 1 A cm⁻² at a cell voltage of 1.57 V. These findings provide valuable insights into the potential of RuO₂@IrO_x as a robust and efficient catalyst for green hydrogen production.