Boosting Efficient and Sustainable Alkaline Water Oxidation on W-Coooh-TT Pair Sites Catalyst Synthesized via Topochemical Transformation.

The development of facile methods for constructing highly active, cost-effective catalysts that meet ampere-level current density and durability requirements for an oxygen evolution reaction is crucial. Herein, we posit a general topochemical transformation strategy: the M-Co 9 S 8 single atom catalysts (SACs) are directly converted into M-CoOOH-TT (M  =  W, Mo, Mn, V) pair sites catalysts under the role of incorporating of atomically dispersed high valence metals modulators through potential cycling. Furthermore, in situ X-ray absorption fine structure spectroscopy was used to track the dynamic topochemical transformation process at the atomic level. The W-Co 9 S 8 breaks through the low overpotential of 160 mV at 10 mA cm -2 . A series of pair-site catalysts exhibit a large current density approaching 1,760 mA cm -2 at 1.68 V versus RHE in alkaline water oxidation and achieve a ∼240-fold enhancement in the normalized intrinsic activity compared to that reported CoOOH, and sustainable stability of 1,000 h. Moreover, we confirmed the O-O bond formation via a two-site mechanism, supported by in situ synchrotron radiation infrared and DFT simulations, which breaks the limit of adsorption-energy scaling relationship on conventional single-site. This article is protected by copyright. All rights reserved.