Anodized Steel: The Most Promising Bifunctional Electrocatalyst for Alkaline Water Electrolysis in Industry

Abstract

Electrolysis of water, especially alkaline water electrolysis (AWE), is the most promising technology to produce hydrogen in industry. However, only 4% of the total hydrogen is produced in this way because the electrode materials are expensive, inefficient, or unstable. Here, it is reported that the large‐scale 3D printed martensitic steel (AerMet100) can be the bifunctional electrode for AWE with high catalytic performance, which may dramatically increase the green‐hydrogen percentage in the market and provide strategic planning for energy management. It is found that the martensitic steel by fast anodization (3 min) can realize ultra‐high hydrogen and oxygen evolution reactions (HER and OER), and excellent stability at high current densities. Particularly, this electrocatalyst shows a low overpotential of 3.18 V and long‐term stability over 140 h at 570 mA cm−2 in overall water splitting. Additionally, the treated large‐scale steel can work well under a very high current up to 20 A. This study demonstrates that martensitic steel can be commercialized as a highly efficient catalyst for industrial hydrogen production in AWE, which should provide solutions to the energy crisis and environmental pollution.

Molybdenum-iron–cobalt oxyhydroxide with rich oxygen vacancies for the oxygen evolution reaction

“…42 In contrast to the previously reported OER catalysts, it is found that the catalyst, with the introduction of Fe and Mo dopants, exhibits better OER catalytic performance. 43–48 The capacity of MoFe 0.5 O x Co(OH) 2− x regarding overpotentials is comparable to recently reported Earth-abundant OER catalysts with excellent performance (Table S2, ESI†). The catalytic kinetics of the presented catalysts were further evaluated by the Tafel slopes (Fig.…”

Simultaneous optimization of CoIr alloy nanoparticles and 2D graphitic-N doped carbon support in CoIr@CN by Ir doping for enhanced oxygen and hydrogen evolution reactions

“…And the weak peaks belonging to CoOOH emerge from 1.3 V at around 504, 513, and 596 cm −1 , revealing a partial transformation from hydroxides to oxyhydroxides species. 55–57 Therefore, the new phases of hydroxides and oxyhydroxides are generated on the surface of CoIr@CN-0.20 during the OER process, in which the oxyhydroxide species could contribute to the superb catalytic performance. 55,57…”

“…55–57 Therefore, the new phases of hydroxides and oxyhydroxides are generated on the surface of CoIr@CN-0.20 during the OER process, in which the oxyhydroxide species could contribute to the superb catalytic performance. 55,57…”

“…And the weak peaks belonging to CoOOH emerge from 1.3 V at around 504, 513, and 596 cm À1 , revealing a partial transformation from hydroxides to oxyhydroxides species. [55][56][57] Therefore, the new phases of hydroxides and oxyhydroxides are generated on the surface of CoIr@CN-0.20 during the OER process, in which the oxyhydroxide species could contribute to the superb catalytic performance. 55,57 To further reveal the microstructure and composition transformation of CoIr@CN-0.20 during the OER process, the aer-OER CoIr@CN-0.20 catalyst was probed by XRD, SEM, TEM, and XPS.…”

“…[55][56][57] Therefore, the new phases of hydroxides and oxyhydroxides are generated on the surface of CoIr@CN-0.20 during the OER process, in which the oxyhydroxide species could contribute to the superb catalytic performance. 55,57 To further reveal the microstructure and composition transformation of CoIr@CN-0.20 during the OER process, the aer-OER CoIr@CN-0.20 catalyst was probed by XRD, SEM, TEM, and XPS. Aer a long-term OER electrocatalytic process, the XRD pattern of CoIr@CN-0.20 shows a weaker reection of the metallic Co phase and no additional new peaks, indicating that some crystalline Co remains and a new oxidic amorphous phase has formed (Fig.…”