\nJoint press release by Hokkaido University and University of Technology Sydney
\nA catalyst that significantly enhances ammonia conversion could improve wastewater treatment, green chemical and hydrogen production.
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\nA team of scientists have developed an effective catalyst with a remarkable ability to enhance the efficiency of ammonia conversion. Published in Advanced Energy Materials, the study reveals the catalyst\u2019s potential to significantly advance wastewater treatment, green nitrite and nitrate, as well as hydrogen production.
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\nCatalysts are substances that speed up chemical reactions by providing a more efficient route for a reaction to occur and making it easier to start and finish. Since catalysts are neither consumed nor altered in the reaction, they can be used repeatedly, and they are essential in a variety of industrial, environmental, and biochemical processes.
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\nThe team, which included researchers from Japan\u2019s Hokkaido University, Australia\u2019s University of Technology Sydney and elsewhere, developed the catalyst, called NiOOH-Ni, by combining nickel (Ni) with nickel oxyhydroxide.
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\nAmmonia can cause severe environmental problems, such as excessive algal growth in water bodies, which depletes oxygen and harms aquatic life. At high concentrations, ammonia can harm humans and wildlife. Effective management and conversion of ammonia are thus critical, but its corrosive nature makes it difficult to handle.
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\nThe researchers developed NiOOH-Ni using an electrochemical process. Nickel foam, a porous material, was treated with an electrical current while immersed in a chemical solution. This treatment resulted in the formation of nickel oxyhydroxide particles on the foam\u2019s surface. Despite their irregular and non-crystalline structure, these nickel-oxygen particles significantly enhance ammonia conversion efficiency. The catalyst\u2019s design allows it to operate effectively at lower voltages and higher currents than traditional catalysts.
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\n\u201cNiOOH-Ni works better than Ni foam, and the reaction pathway depends on the amount of electricity (voltage) used,\u201d explains Professor Zhenguo Huang from the University of Technology Sydney, who led the study. \u201cAt lower voltages, NiOOH-Ni produces nitrite, while at higher voltages, it generates nitrate.\u201d
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\nThis means the catalyst can be used in different ways depending on what is needed. For example, it can be used to clean wastewater by converting ammonia into less harmful substances. But in another process, it can also be used to produce hydrogen gas, a clean fuel. This flexibility makes NiOOH-Ni valuable for various applications.
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\n\u201cNiOOH-Ni is impressively durable and stable, and it works well even after being used multiple times,\u201d says Associate Professor Andrey Lyalin from Hokkaido University, who was involved in the study. \u201cThis makes it a great alternative to traditional, more expensive catalysts like platinum, which aren\u2019t as effective at converting ammonia.\u201d
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\nThe catalyst\u2019s long-term reliability makes it suitable for large-scale industrial use, potentially transforming how industries handle wastewater and produce clean energy.
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\nOriginal Article:
\nH. Liu, C.-J. Yang, C.-L. Dong, J. Wang, X. Zhang, A. Lyalin, T. Taketsugu, Z. Chen, D. Guan, X. Xu, Z. Shao, and Z. Huang, “Electrocatalytic Ammonia Oxidation to Nitrite and Nitrate with NiOOH-Ni. Advanced Energy Materials”, August 7, 2024.
\nDOI: 10.1002\/aenm.202401675
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\npress release:
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