Chromium-Doped NiBP Micro-Sphere Electrocatalysts for Green Hydrogen Production under Industrial Operational Conditions.

Abstract

Wide spread adaptation of green hydrogen can help to mitigate the serious climate issues, increasing global energy demands and the development of advanced electrocatalysts robust under industrial conditions is one of the key technological challenges. Herein, chromium-doped nickel-boride-phosphide (Cr/NiBP) micro sphere (MS) electrocatalyst is demonstrated via a two-step hydrothermal approach along with post-annealing. The Cr/NiBP MS demonstrates low hydrogen evolution reaction and oxygen evaluation reaction over potentials of 78 and 250 mV at 100 mA cm^-2 in 1 m KOH, out performing most of the reported catalysts. The Cr/NiBP ǁ Cr/NiBP exhibits only 1.54 V at 100 mA cm^-2 in 1 m KOH and surpasses the benchmark of RuO₂ (+) ǁ Pt/C (-) up to 2000 mA cm^-2, which sets it as one of the best bifunctional electrocatalysts. Impressively, it maintains stable performance for over 240 h at 1000 mA cm^-2 in 6 m KOH at 60°C, demonstrating rapid response, anti-corrosion resistance, and robust structural integrity to meet the industrial operational conditions. Further, Cr/NiBP ǁ Pt/C exhibits a super-low cell-voltage of 2.25 V at 2000 mA cm^-2. The small amount of Cr atoms incorporation can significantly enhance active sites and intrinsic properties, accelerating water dissociation and rapid intermediate formation.