Phosphorus Defect Mediated Electron Redistribution to Boost Anion Exchange Membrane-Based Alkaline Seawater Electrolysis

It is of essential importance to design bifunctional electrocatalysts with excellent performance for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in seawater splitting. Herein, an approach for manipulating electron redistribution in NiCoP treated by P defect (P-v) engineering (NiCoPv@NF) is presented, exhibiting excellent catalytic activities and stability toward HER/OER in alkaline seawater solution. The P-v reduces the surface electrooxidation reconfiguration energy barrier, making it easier to drive the local conversion of crystals to active oxy(hydroxide) in OER. In addition, the Ni site of NiCoPv and the Co site of NiCoOOH are the active sites for HER and OER processes, respectively. In situ generated PO43- adsorbed on the catalyst surface causes spatial repulsion, preventing Cl- corrosion in seawater electrolysis. The seawater AEM electrolyzer using NiCoPv@NF couple achieves excellent performance of high activity (2.43 V at 500 mA cm(-2)) and long-term durability (500 mA cm(-2) over 110 h). The working efficiency of AEM in 1.0 M KOH is as high as 77.0% at 100 mA cm(-2) with the price of per GGE H-2 as low as $ 0.87.