In-Operando Self-Healing Electrocatalysts
Materials with the capacity for self-healing are of great interest in many different fields of science and technology. In catalysis, combatting the tendency for the activity of as-synthesized catalyst materials to degrade over time under operational conditions remains one of the most difficult challenges for the development of really efficient, impactful catalysis. Where there are catalysts that have the capacity for self-healing and retaining excellent activity, we need to know about it in order to understand and then exploit the principle. In a collaboration between IMDC at UNSW Sydney and KAUST, Hassan Tahini, Xin Tan, Udo Schwingenschloegl and Sean Smith have uncovered just such a self-healing mechanism in perovskite metal oxide electrocatalysts. In their recent article highlighted on the back cover of the April edition of PARTICLE, Smith and co-workers use first-principle simulations to reveal an electrochemical annealing/self-healing mechanism occurring at the surface of SrCoO3, a promising electrocatalyst for oxygen evolution reactions (OER). Vacancies that easily form on the surface are oxidatively quenched through formation of adsorbed atomic oxygen species just before the onset of OER, which heals the surface and restores the anticipated high activity of the pristine surface.