Tailoring the Ionic Liquid Environment in Nanopores for Green Reaction Engineering

1604491PI：Rankin，Stephen E.标题：为绿色反应工程量身定制纳米孔中的离子液体环境离子液体(ILS)是一种熔化温度较低的盐，因此它们可以在室温或接近室温时用作溶剂。ILS因其低挥发性而被认为是绿色溶剂，但也具有独特的可调性质，使其可用于替代物质很少的应用，如木质纤维生物质的增溶和催化转化为商品化学品。最近，ILS的分子和纳米尺度的结构和动力学特征被确定，这表明它们同时具有电荷和极性的共存结构域，这可能解释了为什么它们能够溶解两亲性聚合物，如纤维素和木质素。引入表面会导致界面上的密度和电荷分层，从而产生振荡表面力和精确调整表面性质的能力。建议的工作集中在调整ILS与限制在纳米孔中的金属络合物接触的这些表面性质，以提供高催化性能和稳定性的局部环境。纳米多孔载体在催化剂的局部化过程中提供控制，为调节反应活性和控制底物、反应物和产品的分配创造了独特的环境。该项目将把受限离子液体独特的局部溶剂和层状电子性质转化为多相催化，解决离子液体商业应用的主要限制。受限孔中的溶剂环境与相应的催化活性之间的关系将被应用于挑战水基催化剂。D-葡萄糖脱水生成5-羟甲基呋喃(HMF)将被作为模型反应。提出了以下工作：(1)构建、表征和控制离子液体和含咪唑环的离子液体在纳米孔径中的局部环境。具有定向、可调纳米孔(2-20 nm)的表面活性模板化二氧化硅薄膜将作为表征局部环境和随后在离子液体中催化的平台。(2)设计IL/金属配体和相应的硅烷，将ILS中的均相催化转化为有效、稳定的纳米孔中的多相催化剂。将研究使用无毒的铝基催化剂将葡萄糖脱水成HMF，目的是改善其催化性能，使其成为传统有毒催化剂的可行替代品。(3)展示了葡萄糖在水相中对HMF的催化作用，并开发了一种受限的IL孔环境，最大限度地减少了因水吸收而导致的催化剂失活和浸出。拟议的研究项目有可能产生创新的绿色/可持续化学和工程技术，在催化、能量储存、光伏、气体分离和二氧化碳捕获方面具有广泛的应用。其中包括开发基于视频的交流程序(Video-CAT)的多方面计划，该计划将培训学生如何向不同的受众传播科学，造福于社会。

1604491PI: Rankin, Stephen E. Title: Tailoring the Ionic Liquid Environment in Nanopores for Green Reaction EngineeringIonic liquids (ILs) are salts with a low melting temperature such that they can be used as solvents at or near room temperature. ILs are considered green solvents because of their low volatility, but also have unique and tunable properties that allow them to be used in applications where few alternatives are available, such as the solubilization and catalytic conversion of lignocellulosic biomass to commodity chemicals. Recently, molecular and nanometer-scale structural and dynamic features of ILs have been identified that indicate coexisting domains of both charge and polarity, which may explain why they are able to dissolve amphiphilic polymers, such as cellulose and lignin. Introducing a surface leads to density and charge layering at the interface giving rise to oscillatory surface forces and the ability to precisely tune surface properties. The proposed work focuses on tuning these surface properties for ILs in contact with metal complexes confined in nanopores to provide a local environment for high catalytic performance and stability. Nanoporous supports provide control in localizing a catalyst, creating a distinct environment for tuning reactivity and controlling the partitioning of substrates, reactants and products. This project will translate the unique local solvent and layered electronic properties of confined ILs to heterogeneous catalysis, addressing the major limitations of the commercial applications of ILs. The relationship between the solvent environment in the confined pore and the corresponding catalytic activity will be applied to challenging aqueous-based catalysis.The dehydration of D-glucose to 5-hydroxymethylfurfural (HMF) will be used as a model reaction. The following tasks are proposed: (1) Construction, characterization and control the local environment of ionic liquids and tethered imidazolium-based ionic liquids in nanoscale pores as a function of pore size. Surfactant templated silica thin films with oriented, tunable nanopores (2-20 nm) will serve as the platform for characterization of the local environment and subsequent catalysis in ionic liquids. (2) Design of IL/metal ligands and their corresponding silanes to translate homogeneous catalysis in ILs to effective, stable heterogeneous catalysts in nanoscale pores. The dehydration of glucose to HMF using non-toxic aluminum-based catalysts will be investigated, with a goal of improving its catalytic performance to make it a viable alternative to traditional toxic catalysts. (3) Demonstration of the catalysis of glucose to HMF from the aqueous phase and development of a confined IL pore environment that minimizes catalyst deactivation and leaching due to water uptake.The proposed research project has the potential to generate innovative green/sustainable chemistry and engineering technologies for a broad range of applications in catalysis, energy storage, photovoltaics, gas separations, and carbon dioxide capture. Multi-faceted plans to develop a video-based communication program (video-CATS) are included, which will train students on how to communicate science for the benefit of society to a diverse audience.