Electron‐Rich Platinum Atoms in Lattice of Nickel‐Iron Layered Double Hydroxide Enhance Seawater Electrolysis

ABSTRACT Electrocatalytic hydrogen (H 2 ) evolution reaction (HER) in seawater is among the most attractive ways to produce H 2 , but its efficiency is still far below commercialization need. Herein, platinum (Pt) atoms are doped in lattice of nickel‐iron layered double hydroxide (NiFe‐LDH) to form a PtNiFe‐D15 catalyst with 0.98 wt.% Pt. In HER in alkaline seawater, overpotential to drive industrial‐level current density of 1000 mA cm −2 on PtNiFe‐D15 is 217 mV, which is much lower than those on commercialized 20 wt.% Pt/carbon catalyst (489 mV) and catalysts reported widely. Moreover, PtNiFe‐D15 has faster kinetics and better stability. Doping Pt atoms in NiFe‐LDH lattice forms Ni atoms with empty electronic orbitals and electron‐rich Pt atoms benefit for water splitting, hydroxyl desorption and H 2 desorption. This enhances seawater‐based HER efficiency on PtNiFe‐D15. PtNiFe‐D15 is also used as cathode to form an anion exchange membrane water electrolyzer (AEMWE). In alkaline seawater electrolysis, the AEMWE shows a superior stability, with the potential to drive 1000 mA cm −2 being 1.75 V, which is lower than those in systems reported widely. This provides a great potential for commercialization.