Advancing Spin Controlled Electrocatalysis Using Chiral Gold Nanoparticles Functionalized Bimetallic Spinel Oxide

Abstract

Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are the foundations of renewable energy technology. However, both processes have significant activation barriers, severely limiting the overall performance of energy conversion devices that utilize ORR/OER. Though traditional catalyst design prioritizes crystal and electronic structure, understanding the detailed mechanism requires consideration of spin selection rules as the ground electronic state of diatomic oxygen is a triplet. Here, we demonstrate the enhancement of the electrocatalytic performance of Mn and Co-based bimetallic spinel oxides by functionalizing with chiral gold nanoparticles. Chiral gold nanoparticles impart spin selective charge transfer during oxygen reduction, resulting in higher current density in comparison with the achiral composite catalyst. Furthermore, the onset potential gets reduced by 120 mV at 2.5 mA cm⁻² current density toward the OER activity of the chiral gold nanoparticle functionalized catalyst, attributed to the spin polarization mechanisms via chiral induced spin selectivity effect. This work emphasizes the use of chirality in the transition metal-based oxide to induce the spin polarization in the oxide-based catalysts in advancing ORR and OER efficiencies that are very essential for the application in renewable energy technology.