Electrochemical Oxidation in Room Temperature Ionic Liquids

该项目的目标是展示环境可接受的氯化溶剂完全氧化的环境修复方法。活性氧物种将是超氧离子，它将在非质子室温离子液体中使用合适的阴极产生。除了展示氯化污染物的完全氧化外，使用相同的超氧化物化学的部分电化学氧化将为合成有机分子提供一条途径，这些有机分子是羧酸的功能衍生物。PI将在新型离子液体溶剂中通过电化学产生超氧离子来进行废物的低温氧化。废溶剂的低温氧化将为高温垃圾焚烧炉提供一种急需的替代方案，高温垃圾焚烧炉的使用因监管要求和选址而变得非常复杂。此前在二甲基甲酰胺和乙腈等挥发性和环境可疑的非质子溶剂中已经证明了这种超氧化物化学。然而，离子液体是非挥发性和不可燃的，应该最大限度地减少二次溶剂浪费和产品与溶剂分离的问题。假设超氧化物的基本电化学是成功的，则进一步提出通过二氧化碳(CO2)和氧气的电化学活化，然后适当的底物的羧化来进行有机合成。要合成的分子类别是碳酰胺，它们是药品和农用化学品等消费品生产中有价值的中间体。目前的商业过程可能需要有机溶剂、昂贵的催化剂，甚至需要光气来合成这些中间体。因此，有一个更好的、可持续的方法来制造这些中间体的强烈动机。该项目支持开发一种清洁和环境友好的技术，用于废物修复和基于超氧化物化学的化学制造。该项目将包括一名研究生，一名博士后，以及通过南卡罗来纳大学化学工程系现有的NSF REU项目的本科生。

The objective of this project is to demonstrate environmentally-acceptable methods for complete oxidation of chlorinated solvents for environmental remediation. The active oxygenation species will be superoxide ion, which will be generated in an aprotic room temperature ionic liquid using a suitable cathode. In addition to demonstrating complete oxidation of chlorinated pollutants, partial electrochemical oxidation using the same superoxide chemistry will provide a route for synthesis of organic molecules that are functional derivatives of carboxylic acids.The PI will conduct low-temperature oxidation of wastes via electrochemical generation of superoxide ion in novel ionic liquid solvents. Low-temperature oxidation of waste solvents will provide a much-needed alternative to high temperature waste incinerators, whose use is greatly complicated by regulatory requirements and locating suitable sites. Such superoxide chemistry has previously been demonstrated in volatile and environmentally-suspect aprotic solvents such as dimethyl formamide and acetonitrile. However, ionic liquids are non-volatile and non-flammable, and should minimize the problems of secondary solvent waste and separation of products from solvent. Assuming the basic electrochemistry of superoxide is successful, it is further proposed to conduct organic synthesis by electrochemical activation of carbon dioxide (CO2) and oxygen, followed by carboxylation of appropriate substrates. The classes of molecules to be synthesized are carbamides, which are valuable intermediates in the production of consumer products such as pharmaceuticals and agrichemicals. Present commercial processes may require organic solvents, expensive catalysts, or even phosgene in the synthesis of these intermediates. There is thus a strong motivation for better, sustainable approaches to manufacture of these intermediates.This project supports the development of a clean and environmentally friendly technology for both waste remediation and chemical manufacturing, based on superoxide chemistry. The project will involve a graduate student, a post-doctoral student, and undergraduate students through an existing NSF REU program in the Department of Chemical Engineering at the University of South Carolina.