SusChEM: Non-precious metal substitution into hydrogenation metal alloy catalysts deposited onto redox active supports for facile nitrate destruction in drinking water

美国公司每年花费近30亿美元购买和制造减少催化剂，以帮助生产燃料、肥料和药品。考虑到这项投资和已证明的成功，这些催化剂没有用于生产饮用水可能令人惊讶。相反，目前的饮用水处理方法既昂贵又有可能危害环境。还原催化剂不用于净水的主要原因是它们是由贵金属制成的，成本也很高，而水是一种低价值产品。本工作的研究目标是通过用廉价的金属还原催化剂代替贵金属，以最低的成本和对环境的最小危害实现处理目标，从而推进水处理科学。这些催化剂将用于处理硝酸盐，这是世界上最常见的地下水污染物，主要来自农业肥料。学生研究人员将接受培训，成为这项技术的未来领导者，这样他们就可以培训其他人设计更有效的水处理厂。提出的工作的主要目标是推进支撑金属合金催化处理普遍存在的水污染物硝酸盐的科学。具体目标是：1)开发具有较高硝酸还原活性的新型金属合金纳米颗粒催化剂；2)确定能提高合金金属纳米颗粒水处理催化活性和稳定性的电子活性载体；3)采用生命周期评价方法对新型催化剂的环境影响和成本进行评价。为了实现这些目标，将使用一种新的微波辅助方法合成一套具有晶格取代的半贵金属和非贵金属的铂族金属基合金纳米颗粒。催化剂将被负载在一系列氧化还原活性载体上，并使用先进的显微/光谱技术进行表征。对新催化剂的硝酸和亚硝酸盐还原动力学以及对氨的选择性进行了评价。结果将与催化剂性能进行比较，并用密度泛函理论进行解释，以确定控制机制。将在实际水处理条件下评估催化剂的长期稳定性，并将结果用于进行经济和环境生命周期评估。所提出的工作将导致新的基础知识：1)氢活性金属对催化的影响；2)氧化还原活性载体对合金金属纳米颗粒活性和稳定性的影响；3)定量评价了金属合金对饮用水催化处理成本和可持续性的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

United States companies spend almost $3 billion a year buying and making reduction catalysts to help create fuel, fertilizers, and medicines. Given this investment and proven success, it is perhaps surprising that these catalysts are not used to produce potable drinking water. Instead, current drinking water treatment methods are costly and have potential to harm the environment. The main reason reduction catalysts are not used to clean water is because they are made from precious metals that also have a high cost, and water is a low value product. The research goal of this work is to advance the science of water treatment by replacing precious metals with inexpensive metal reduction catalysts to achieve treatment goals at the lowest cost and with the least harm to the environment. The catalysts will be used to treat nitrate, the most common groundwater pollutant in the world that results primarily from agricultural fertilizer. Student researchers will be trained to become future leaders in this technology, so they can train others to design more effective water treatment plants.The primary goal of the proposed work is to advance the science of supported metal-alloy catalysis for the treatment of the ubiquitous water pollutant nitrate. The specific objectives are to 1) develop new metal alloy nanoparticle catalysts with markedly higher catalytic activity for nitrate reduction; 2) identify electronically active supports that enhance catalytic activity and stability of alloy metal nanoparticles for water treatment; and 3) evaluate the environmental impacts and costs of the new catalysts using life cycle assessment. To address these objectives, a suite of platinum group metal-based alloy nanoparticles with lattice substituted semi- and non-precious metals will be synthesized using a novel microwave-assisted method. The catalysts will be supported on a series of redox active supports and characterized using advanced microscopic/spectroscopic techniques. The new catalysts will be evaluated with/without amended indium for nitrate and nitrite reduction kinetics, and selectivity for ammonia. The results will be compared to catalyst properties and interpreted with density functional theory to identify controlling mechanisms. Long-term catalyst stability will be evaluated under realistic water treatment conditions, and the results used to perform economic and environmental life cycle assessments. The proposed work will result in new fundamental knowledge regarding 1) the effects of hydrogenation-inactive metals on catalysis; 2) the influence of redox active supports on alloy metal alloy nanoparticle activity and stability; and 3) a quantitative assessment of the effects of metal alloys on cost and sustainability of catalytic treatment of drinking water.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.