Realizing the Tailored Catalytic Performances on Atomic Pt-Promoted Transition Metal Moieties Implanted Layered Double Hydroxides for Water Electrolysis
Dang Khoa Tran, Thanh Hai Nguyen, Duy Thanh Tran, Van An Dinh, Nam Hoon Kim, Joong Hee Lee
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 d -band center with the low valence states of Pt SA(doped) and Pt SA(ads.), thus optimizing adsorption energy to effectively accelerate the H 2 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 H 2 O 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.