Locking the lattice oxygen in RuO2 to stabilize highly active Ru sites in acidic water oxidation

Ruthenium dioxide is presently the most active catalyst for the oxygen evolution reaction (OER) in acidic media but suffers from severe Ru dissolution resulting from the high covalency of Ru-O bonds triggering lattice oxygen oxidation. Here, we report an interstitial silicon-doping strategy to stabilize the highly active Ru sites of RuO 2 while suppressing lattice oxygen oxidation. The representative Si-RuO 2 −0.1 catalyst exhibits high activity and stability in acid with a negligible degradation rate of ~52 μV h −1 in an 800 h test and an overpotential of 226 mV at 10 mA cm −2 . Differential electrochemical mass spectrometry (DEMS) results demonstrate that the lattice oxygen oxidation pathway of the Si-RuO 2 −0.1 was suppressed by ∼95% compared to that of commercial RuO 2 , which is highly responsible for the extraordinary stability. This work supplied a unique mentality to guide future developments on Ru-based oxide catalysts’ stability in an acidic environment. RuO 2 is highly active toward the acidic electrochemical oxygen evolution reaction but exhibits instability due to lattice oxygen oxidation. Here, authors prepare an interstitial Si-decorated RuO 2 catalyst with improved stability for acidic water oxidation by suppressing lattice oxygen oxidation.