CAREER: Single-Atom Alloy Nanocrystals for Catalyzing Sustainable Nitrogen Cycling

职业：用于催化可持续氮循环的单原子合金纳米晶体

• 批准号: 2317302
• 负责人: Huiyuan Zhu
• 金额: $ 59.29万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-15 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317302&HistoricalAwards=false
• 关键词: CAREER; Single; Atom; Alloy; Nanocrystals

The industrial production of fertilizer – produced from ammonia (NH3) generated by the energy-intensive, fossil fuel-dependent Haber-Bosch (H-B) process - has disrupted the natural nitrogen cycle, resulting in groundwater pollution from nitrates (NO3-). The project utilizes electrochemistry to react nitrate compounds with hydrogen (derived sustainably from water) to manufacture NH3, while simultaneously decomposing the nitrate pollutants and restoring balance to the nitrogen cycle. Specifically, the research focuses on the discovery and design of catalysts that enable efficient nitrate-to-ammonia transformation driven by renewable electricity. Beyond the technical aspects, the project will train students from diverse groups at the interface of catalysis, chemistry, and engineering. The research will be integrated with educational and outreach efforts to illustrate the importance of sustainability in daily life while stimulating excitement for STEM amongst K-12 youth, especially those from low-income families. The electrochemical nitrate reduction reaction (NO3RR) offers a potentially attractive distributed NH3 production route, because it utilizes nitrate pollutants as the N-source, thus circumventing activation of the strong N≡N triple bond associated with the H-B process. The project will develop design strategies for single-atom alloy (SAA) electrocatalysts for the NO3RR and advance the fundamental understanding of both the catalytic active sites and the elementary mechanisms. The project is built on the central hypothesis that surface doping of Cu nanocrystals with isolated metal atoms (for example, Pt, Pd, Rh, or Ru) creates well-defined sites that activate water molecules and generate H-atoms that spill over to the Cu. The H-atoms hydrogenate N-species at low overpotentials and selectively tailoring of the binding strength of NO3RR surface intermediates through narrowly distributed d-states of single atoms for high-rate production of NH3, can potentially go beyond adsorption-energy scaling limitations. Catalyst synthesis, characterization, and electrochemical evaluation will be facilitated by advanced characterization techniques including operando surface-enhanced infrared absorption spectroscopy, differential electrochemical mass spectrometry, in-situ X-ray absorption spectroscopy, advanced electron microscopy, and computational tools such as density functional theory. The educational components of the project include (1) integrating research into the curriculum, (2) interdisciplinary student training, (3) involving diverse underrepresented students in science and engineering, and (4) implementing STEM-based outreach programs through the Center for Enhancement of Engineering Diversity at Virginia Tech and summer programs at Wonder Universe: A Children’s Museum. In addition, the newly launched Virginia Clean Energy and Catalysis Club will be leveraged as a platform to promote student training. The outreach plan also includes the development of an interactive play-based pedagogical platform, “Sustainable City in Minecraft,” that will provide young students the opportunity to design and construct a futuristic sustainable city.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.

肥料的工业生产——由能源密集型、依赖化石燃料的哈伯-博世 (H-B) 工艺产生的氨 (NH3) 产生的——扰乱了自然氮循环，导致硝酸盐 (NO3-) 项目污染地下水。利用电化学使硝酸盐化合物与氢（可持续地从水中提取）反应来制造 NH3，同时分解硝酸盐污染物并恢复氮循环的平衡。研究重点是发现和设计催化剂，以实现由可再生电力驱动的高效硝酸盐到氨的转化。除了技术方面之外，该项目还将在催化、化学和工程方面对来自不同群体的学生进行培训。与教育和宣传工作相结合，以说明可持续性在日常生活中的重要性，同时激发 K-12 青少年（尤其是来自低收入家庭的青少年）对 STEM 的兴趣。电化学硝酸盐还原反应 (NO3RR) 提供了一种具有潜在吸引力的分布式 NH3 生产。路线，因为它利用硝酸盐污染物作为氮源，从而避免了与 H-B 过程相关的强 N=N 三键的活化。该项目将开发用于 NO3RR 的单原子合金 (SAA) 电催化剂的设计策略，并推进基础研究。该项目建立在铜纳米晶体表面掺杂孤立金属原子（例如 Pt、Pd、 Rh（或 Ru）创建明确的位点，激活水分子并生成溢出至 Cu 的 H 原子。H 原子在低过电势下氢化 N 物质，并通过窄范围选择性调整 NO3RR 表面中间体的结合强度。用于高速率生产 NH3 的分布式 d 态可能会超越吸附能缩放限制 先进的表征技术（包括）将有助于催化剂合成、表征和电化学评估。操作表面增强红外吸收光谱、微分电化学质谱、原位 X 射线吸收光谱、先进电子显微镜以及密度泛函理论等计算工具。该项目的教育组成部分包括 (1) 将研究纳入课程。 ，(2) 跨学科学生培训，(3) 涉及科学和工程的多元化学生，以及 (4) 通过弗吉尼亚理工大学工程多样性增强中心实施基于 STEM 的外展计划，以及奇妙宇宙：儿童博物馆的暑期项目还将利用新推出的弗吉尼亚清洁能源和催化俱乐部作为促进学生培训的平台，该推广计划还包括开发一个基于游戏的互动教学平台。 “我的世界中的可持续城市”，将为年轻学生提供设计和建造未来可持续城市的机会。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Synthesis of core/shell nanocrystals with ordered intermetallic single-atom alloy layers for nitrate electroreduction to ammonia

• DOI: 10.1038/s44160-023-00258-x
• 发表时间: 2023-07-01
• 期刊: NATURE SYNTHESIS
• 作者: Gao, Qiang;Yao, Bingqing;Zhu, Huiyuan
• 通讯作者: Zhu, Huiyuan