Lewis-basic PO43− induced interfacial water dissociation on CoWO4 for enhanced neutral oxygen evolution reaction

Lewis-basic PO 4 3− regulates interfacial water on CoWO 4 for neutral OER. • PO 4 3− -CoWO 4 reaches 330 mV at 10 mA cm −2 and operates stably for 250 h. • PO 4 3− increases interfacial free water and promotes water dissociation. • Enhanced surface *OH coverage accelerates neutral OER kinetics. • PO 4 3− suppresses Co/W leaching and improves catalyst stability. In neutral water electrolysis, the intrinsically low OH − concentration compels the oxygen evolution reaction (OER) to proceed via an additional water dissociation step, leading to sluggish kinetics and high overpotential, which poses a challenge for efficient catalyst design. Introducing Lewis base sites on the catalyst surface can act as proton acceptors, accelerating H OH bond cleavage and thereby promoting the generation and accumulation of *OH. Herein, we incorporated the Lewis base PO 4 3− into CoWO 4 to construct a self-supporting PO 4 3− -CoWO 4 electrode. The incorporated PO 4 3− engages in electronic interactions with Co/W active sites, modulating the local electronic structure. Electrochemical tests demonstrate that PO 4 3− -CoWO 4 exhibits outstanding OER performance in 1 M phosphate buffer solution (PBS), achieving an overpotential of only 330 mV at 10 mA cm −2 and stable operation over 250 h. Mechanistic studies reveal that PO 4 3− optimizes the interfacial water on CoWO 4 , increases the fraction of free water, facilitates water dissociation, and enhances the surface *OH coverage. Moreover, it effectively suppresses the leaching of active Co/W species during OER, thereby improving the structural stability of the catalyst. This interfacial regulation by PO 4 3− synergistically boosts the activity and stability of neutral OER, providing new insights for designing highly efficient neutral water electrolysis catalysts. Lewis base PO 4 3− accelerates water dissociation on CoWO 4 , enabling neutral OER with an overpotential of 330 mV and 250 h durability. Download: Download high-res image (154KB) Download: Download full-size image