Ternary Ni‐Mo‐P catalysts for enhanced activity and durability in proton exchange membrane water electrolysis

Abstract

Summary Proton‐exchange membrane water electrolyzers with active and stable non‐precious catalysts are necessary to produce cheap and efficient hydrogen from water electrolysis. In this study, Ni‐Mo‐P ternary alloy catalysts with a wide composition range are fabricated by electrodeposition. Their activity and stability as hydrogen evolution catalysts are evaluated at the level of both half and single cells. We prove that the morphologies, crystalline structures, and electronic status of the electrodeposited catalysts, which play important roles in the catalytic activity and stability, significantly vary with the compositions of the ternary system. The best performing NiMoP catalyst with an optimal composition exhibited a half‐cell performance of 28 mV overpotential at −10 mA cm−2 and a single‐cell performance of 2 Vcell at 1.87 A cm−2, which is superior to the previously reported NiP‐ and MoP‐based electrolyzers. Due to the addition of corrosion‐resistant P, the NiMoP catalyst exhibited exceptional stability of 3 mV h−1 for 48 hours at 1 A cm−2. As a result, the novel ternary Ni‐Mo‐P catalyst prepared by a simple and low‐cost synthesis method is a strongly promising candidate for non‐precious hydrogen evolution catalysts in proton exchange membrane water electrolyzers.

Design and multilevel regulation of transition metal phosphides for efficient and industrial water electrolysis

“…Heterogeneous atoms (Mo and P) and their optimal composition give Ni 71.5 Mo 26.5 P 2 an amorphous structure and morphology. 132 The addition of Mo and P can change the electronic state of Ni 71.5 Mo 26.5 P 2 , and enhance the activity and stability of the HER. Ni 71.5 Mo 26.5 P 2.0 (HER)‖IrO 2 achieves a current density of 1.87 A cm −2 at a battery voltage of 2.0 V. Moreover, the stability was maintained for 48 h at 1 A cm −2 , where the battery voltage was only increased by 0.16 V. By means of pulse electrodeposition, Ni defects can be selectively dissolved in nickel-rich areas of the Ni–P catalyst, and the relative content of P can be increased.…”

Benchmarking Molybdenum-Based Materials as Cathode Electrocatalysts for Proton Exchange Membrane Water Electrolysis: Can These Compete with Pt?

“…To overcome the challenge imposed by the usage of noble metals, there has been immense efforts to produce earth-abundant electrocatalysts suitable for the PEMWE technology. − Molybdenum, an earth-abundant and low-cost metal, has already been used to produce highly active HER electrocatalysts that are considered potential candidates to replace Pt. Three of the most promising Mo-based nanomaterials that can compete with Pt are: (i) 1T′-MoS 2 , (ii) Co-MoS 2 , and (iii) β-Mo 2 C. All of these materials exhibit high stability under acidic conditions, relatively low HER onset potential, and small Tafel slopes when studied in conventional three-electrode cells.…”