Realizing the Tailored Catalytic Performances on Atomic Pt-Promoted Transition Metal Moieties Implanted Layered Double Hydroxides for Water Electrolysis.

Abstract

High-performance production of green hydrogen gas is necessary to develop renewable energy generation technology and to safeguard the living environment. This study reports a controllable engineering approach to tailor the structure of nickel-layered double hydroxides via doped and absorbed platinum single atoms (Pt_SA) promoted by low electronegative transition metal (Mn, Fe) moieties (Pt_SA-Mn,Fe-Ni LDHs). We explore that the electron donation from neighboring transition metal moieties results in the well-adjusted <i>d</i>-band center with the low valence states of Pt_SA(doped) and Pt_SA(ads.), thus optimizing adsorption energy to effectively accelerate the H₂ release. Meanwhile, a tailored local chemical environment on transition metal centers with unique charge redistribution and high valence states functions as the main center for H₂O catalytic dissociation into oxygen. Therefore, the Pt_SA-Mn,Fe-Ni LDH material possesses a small overpotential of 42 and 288 mV to reach 10 mA·cm^-2 for hydrogen and oxygen evolution, respectively, superior to most reported LDH-based catalysts. Additionally, the mass activity of Pt_SA-Mn,Fe-Ni LDHs proves to be 15.45 times higher than that of commercial Pt-C. The anion exchange membrane electrolyzer stack of Pt_SA-Mn,Fe-Ni LDHs_(+,-) delivers a cell voltage of 1.79 V at 0.5 A·cm^-2 and excellent durability over 600 h. This study presents a promising electrocatalyst for a practical water splitting process.