Molecular-level proton acceptor boosts oxygen evolution catalysis to enable efficient industrial-scale water splitting

Industrial water splitting has long been suppressed by the sluggish kinetics of the oxygen evolution reaction (OER), which requires a catalyst to be efficient. Herein, we propose a molecular-level proton acceptor strategy to produce an efficient OER catalyst that can boost industrial-scale water splitting. Molecular-level phosphate (-PO4) group is introduced to modify the surface of PrBa0.5Ca0.5Co2O5+δ (PBCC). The achieved catalyst (PO4-PBCC) exhibits significantly enhanced catalytic performance in alkaline media. Based on the X-ray absorption spectroscopy results and density functional theory (DFT) calculations, the PO4 on the surface, which is regarded as the Lewis base, is the key factor to overcome the kinetic limitation of the proton transfer process during the OER. The use of the catalyst in a membrane electrode assembly (MEA) is further evaluated for industrial-scale water splitting, and it only needs a low voltage of 1.66 V to achieve a large current density of 1 A cm−2. This work provides a new molecular-level strategy to develop highly efficient OER electrocatalysts for industrial applications.