Highly active and stable amorphous IrOx/CeO2 nanowires for acidic oxygen evolution

Development of highly active and durable electrocatalysts for acidic oxygen evolution reaction (OER) remains an unresolved grand challenge. Here, we reported the amorphous IrO x /CeO 2 nanowires as highly active and acid-stable OER catalysts through a facile electro-spinning/calcination approach. The amorphous catalysts delivered a high mass activity of 167 A g Ir −1 at 1.51 V, a low overpotential of 220 mV at 10 mA cm −2 , and a stable performance for 300 h of continuous operation in acid. As revealed by complementary experimental and theoretical calculation results, the intimate nanoscale feature of IrO x /CeO 2 creates abundant binary interfaces, at which CeO 2 as an electron buffer regulates the adsorption of oxygen intermediates, lowers the activation barrier of OER, and suppresses the over-oxidation and dissolution of Ir, thereby significantly enhancing the OER activity and stability. This work provides a new strategy for designing highly active and acid-resistant OER catalysts. Amorphous binary IrO x /CeO 2 nanowires synthesized through a facile electro-spinning/calcination method delivered a highly active and stable performance for acidic oxygen evolution, where CeO 2 as an electron buffer not only modulates the adsorption behavior of oxygen intermediates but also stabilizes the Ir oxidation states during the reaction to suppress the dissolution of iridium. • Synthesis of binary amorphous IrO x /CeO 2 nanowires with abundant interfaces. • High catalytic activity and stability of amorphous IrO x /CeO 2 nanowires for acidic OER. • CeO 2 as an electron buffer to suppress the dissolution of Ir and reduce the activation barrier.