Polyoxometalates-derived lattice-confined atomically dispersed catalysts for water electrolysis

Atomically dispersed single-site catalysts (ADCs) have demonstrated exceptional catalytic performance that surpasses traditional catalysts, attributed to their higher atom utilization efficiency. However, a general engineering approach for converting metal-oxo clusters into efficient and stable ADCs has not been established. In this work, a universal conversion strategy is reported to synthesize a series of noble metal ADCs (NM@WO₂−W, NM = Ir, Pt, Ru, and Pd) through the engineering of polyoxometalates (POMs), a well-established type of metal-oxo clusters. This strategy confines the single noble metal atom within the lattice of WO₂, thereby creating lattice-confined ADCs. The as-prepared Pt@WO₂−W exhibits enhanced catalytic activity for the hydrogen evolution reaction (HER), with an impressively low overpotential of 49 mV at 50 mA·cm⁻² and robust durability over 50 h, with only 0.2% current density decay. Furthermore, the catalytic behavior of NM@WO₂−W in the oxygen evolution reaction (OER) has also been explored, highlighting the superior electrocatalytic activity and durability of Ir@WO₂−W. In situ experiments and density functional theory calculations further reveal the intrinsic activity of NM@WO₂−W for both HER and OER. This work introduces a general strategy for the rational design of lattice-confined ADCs through conversion of metal-oxo clusters, providing efficient and stable ADCs for water electrolysis.