CAREER: Understanding and Overcoming the Fundamental Barriers to the Direct Reduction of Aluminum Hydroxide to Aluminum Metal

职业：了解并克服氢氧化铝直接还原为金属铝的基本障碍

• 批准号: 2047851
• 负责人: Eric Detsi
• 金额: $ 59.63万
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047851&HistoricalAwards=false
• 关键词: CAREER; Understanding; Overcoming; Fundamental; Barriers

Aluminum is the second most used metal worldwide after steel, however, aluminum rarely exists in nature in the form of pure metal. Aluminum does abundantly exist in the Earth’s crust in the form of aluminum hydroxide found in bauxite ore from which it is extracted. The 130-year-old method, known as the Bayer (1888) and Hall-Héroult (1886) process, is used to produce aluminum from bauxite, but it is a highly energy- and carbon-intensive industrial process. Production of one kilogram of aluminum consumes over 15 kilowatt-hours of electrical energy and releases up to 14 kilograms of carbon dioxide. Therefore, an alternative process that significantly reduces energy consumption and carbon emissions would greatly impact the economy and utilization of aluminum. This Faculty Early Career Development (CAREER) award supports research to elucidate and overcome the fundamental barriers that impede the direct conversion of aluminum hydroxide to aluminum at room temperature. This is a process that has the potential to shift the conventional aluminum smelting paradigm by avoiding direct carbon emissions and eliminating energy waste in melting the starting and/or intermediate materials. Beyond the positive environmental impact, since most of the aluminum used in the U.S. is imported from countries with cheap hydroelectric power, the lower energy-consumption process proposed here allows the U.S. production of aluminum to be more competitive and benefit the U.S. economy and society. The proposed research is integrated with various education and outreach activities involving the aluminum life cycle, which will be showcased to students with physical disabilities from the Pennsylvania School for the Deaf and underrepresented K-12 students from Philadelphia and its surrounding counties.Thermodynamically, aluminum hydroxide can be electrolytically reduced into aluminum metal at room temperature in a process that involves hydroxide ions and requires an aqueous electrolyte. Unfortunately, the high reactivity of metallic aluminum with water renders the use of an aqueous electrolyte problematic. To overcome this obstacle, an innovative hybrid aqueous/nonaqueous electrochemical cell is being developed and used to achieve direct electrolytic reduction of aluminum hydroxide to aluminum at room temperature. The reaction pathways is studied using X-ray scattering techniques in real time during the reduction process to map the evolution of size, curvature and crystal structure of the aluminum created. In parallel, the reaction overpotentials and interfacial charge transport kinetics will be investigated using electrochemical techniques. The fundamental insights gained from electrochemical measurements and real-time structural characterization based on X-ray scattering will inform process optimization techniques to achieve maximum hydroxide-to-aluminum yield and scalability.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

铝是仅次于钢的全球第二使用的金属，但是，铝很少以纯金属的形式存在。铝确实以铝土矿矿石的氢氧化铝的形式存在于地壳中。这是130年历史的方法，即拜耳（1888）和Hall-Héroult（1886）工艺，用于从铝土矿生产铝，但这是一种高能量和碳强化的工业过程。在15千瓦时的电能中生产一公斤的铝消耗量，并释放多达14公斤的二氧化碳。因此，一个大大降低能源消耗和碳排放的替代过程将极大地影响铝的经济和利用。该教师早期职业发展（职业）奖支持研究和克服阻碍氢氧化铝直接转化为室温下铝的基本障碍。这个过程有可能通过避免直接碳排放并消除融化起始和/或中间材料中的能源浪费来改变常规铝冶炼范式。除了积极的环境影响之外，由于美国使用的大多数铝是从具有廉价水力发电的国家进口的，因此此处提出的较低能源消费过程允许美国生产铝的竞争力，并使美国的经济和社会受益。拟议的研究与涉及铝生命周期的各种教育和外展活动融合在一起，这将向宾夕法尼亚州聋人学校的身体残疾学生展示，而来自费城及其周围县的聋哑学生和代表性不足的K-12学生可以将铝氧化铝含量为氧化铝，使氧化铝含量降低了。并且需要水解物。不幸的是，金属铝与水的高反应性导致使用水解有问题的使用。为了克服这一障碍，正在开发并使用创新的杂化水溶液/非水性电化学细胞，以在室温下直接将氢氧化铝氢氧化铝降低到铝。在还原过程中，使用X射线散射技术实时研究了反应途径，以绘制所产生的铝的大小，曲率和晶体结构的演变。同时，将使用电化学技术研究反应过电势和界面电荷转运动力学。 The fundamental insights gained from electrochemical measurements and real-time structural characterization based on X-ray scattering will inform process optimization techniques to achieve maximum hydroxide-to-aluminum Yield and scalability.This award reflects NSF's statutory mission and has been deemed honestly of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

项目成果

Dealloyed Air- and Water-Sensitive Nanoporous Metals and Metalloids for Emerging Energy Applications

• DOI: 10.1021/acsaem.2c00405
• 发表时间: 2022-06-07
• 期刊: ACS APPLIED ENERGY MATERIALS
• 影响因子: 6.4
• 作者: Fu, Jintao;Welborn, Samuel S.;Detsi, Eric
• 通讯作者: Detsi, Eric

Ultrafine nanoporous aluminum by electrolytic dealloying of aluminum-magnesium alloys in glyme-based electrolytes with recovery of sacrificial magnesium

• DOI: 10.1016/j.scriptamat.2022.114959
• 发表时间: 2022
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Timothy Lee;Hyeong‐Jun Koh;Alexander K. Ng;Jiaxin Liu;E. Stach;E. Detsi

Isolating intermediate Mg11Cu6Al12 phase in ternary Mg-Cu-Al alloy by electrolytic dealloying

• DOI: 10.1016/j.scriptamat.2022.115039
• 期刊: Scripta Materialia
• 影响因子: 6
• 作者: Timothy Lee;Jintao Fu;Lin Wang;Jiaxin Liu;Samuel S. Welborn;J. Weker;E. Detsi