Lattice strain induced by trace Pt single atoms in nickel for accelerating industrial hydrogen evolution

Abstract

Strategically designing the electrocatalytic system and cleverly inducing strain is an effective approach to balance the cost and activity of Pt-based electrocatalysts for industrial-scale hydrogen production. Herein, we present a unipolar pulsed electrodeposition (UPED) strategy to induce strain in the Ni lattice by introducing trace amounts of Pt single atoms (SAs) (0.22 wt%). The overpotential decreased by 183 mV at 10 mA cm−2 in 1.0 M KOH after introducing trace amounts of PtSAs. The industrial electrolyzer, assembled with PtSAsNi cathode and a commercial NiFeOx anode, requires a cell voltage of 1.90 V to attain 1 A cm−2 of current density and remains stable for 280 h, demonstrating significant potential for practical applications. Spherical aberration corrected scanning transmission electron microscopy (AC-STEM), X-ray absorption (XAS), and geometric phase analysis (GPA) indicate that the introduction of trace amounts of Pt SAs induces tensile strain in the Ni lattice, thereby altering the local electronic structure and coordination environment around cubic Ni for enhancing the water decomposition kinetics and fundamentally changing the reaction pathway. The doping-strain strategy showcases conformational relationships that could offer new ideas to construct efficient hydrogen evolution reaction (HER) electrocatalysts for industrial hydrogen production in the future.