Electronic Structure Modulation Induced by Cobalt-doping and Lattice-Contracting on Armor-Like Ruthenium Oxide Drives pH-Universal Oxygen Evolution.

Exquisite design of RuO 2 -based catalysts to simultaneously improve activity and stability under harsh conditions and reduce the Ru dosage is crucial for advancing energy conversion involving oxygen evolution reaction (OER). Herein, a distinctive cobalt-doped RuO x framework is constructed on Co 3 O 4 nanocones (Co 3 O 4 @CoRuO x ) as a promising strategy to realize above urgent desires. Extensive experimental characterization and theoretical analysis demonstrate that cobalt doped in RuO x lattice brings the oxygen vacancies and lattice contraction, which jointly redistribute the electron configuration of RuO x . The optimized d-band center balances the adsorption energies of oxygenated intermediates, lowing the thermodynamical barrier of the rate-determining step; and meanwhile, the over-oxidation and dissolution of Ru species are restrained because of the p-band down-shifting of the lattice oxygen. Co 3 O 4 @CoRuO x with 3.7 wt.% Ru delivers the extremely low OER overpotentials at 10 mA cm -2 in alkaline (167 mV), neutral (229 mV), and acidic electrolytes (161 mV), and super operating stability over dozens of hours. The unprecedented activity ranks first in all pH-universal OER catalysts reported so far. These findings provide a route to produce robust low-loading Ru catalysts and an engineering approach for regulating the central active metal through synergy of co-existing defects to improve the catalytic performance and stability.