Synergistic Effect of Electronic Particle-Support Interactions on the Ir-Based Multiheterostructure for Acidic Water Oxidation

Exploiting durable electrocatalysts with high specific activity for acidic water oxidation is a great challenge due to the high energy barrier for the multiple oxygen evolution reaction (OER) intermediates. Deliberately taking advantage of the synergistic effect of electronic particle-support interactions on both the particle and support may address this concern. Here, we deliberately design a multiheterostructure with an IrO₂ shell-coated Ir core anchored on the Co₃O₄ framework as an efficient acidic OER electrocatalyst. Detailed characterizations (depth-resolved XPS, XANES, and EXAFS) of the electrocatalysts demonstrate that the electronic particle-support interactions lead to a unique electron transfer at the interface from IrO₂ and Co₃O₄ to Ir. Such an electron transfer will result in compressed Ir-O bonds and Co-O bonds, thus simultaneously reducing free energies for OER intermediates on the surfaces of both IrO₂ and Co₃O₄, sufficiently stimulating the synergistic effect to enhance OER activity and stability.