Dynamic rhenium dopant boosts ruthenium oxide for durable oxygen evolution.

Abstract

Heteroatom-doping is a practical means to boost RuO2 for acidic oxygen evolution reaction (OER). However, a major drawback is conventional dopants have static electron redistribution. Here, we report that Re dopants in Re0.06Ru0.94O2 undergo a dynamic electron accepting-donating that adaptively boosts activity and stability, which is different from conventional dopants with static dopant electron redistribution. We show Re dopants during OER, (1) accept electrons at the on-site potential to activate Ru site, and (2) donate electrons back at large overpotential and prevent Ru dissolution. We confirm via in situ characterizations and first-principle computation that the dynamic electron-interaction between Re and Ru facilitates the adsorbate evolution mechanism and lowers adsorption energies for oxygen intermediates to boost activity and stability of Re0.06Ru0.94O2. We demonstrate a high mass activity of 500 A gcata.-1 (7811 A gRe-Ru-1) and a high stability number of S-number = 4.0 × 106 noxygen nRu-1 to outperform most electrocatalysts. We conclude that dynamic dopants can be used to boost activity and stability of active sites and therefore guide the design of adaptive electrocatalysts for clean energy conversions.