SusChEM: Directing the distribution of biomass-derived molecules in porous materials

PI名称：Susannah L.Scott Proposal编号：1512228重要化学品和燃料的大规模可持续生产可以通过使用非食品类生物质等可再生资源来实现。利用多孔固体催化剂在液态水中选择性地将生物质衍生碳水化合物转化为特定化学品的过程部分受到生物质衍生碳水化合物分子进入催化剂多孔结构的分子运动以及产物移出多孔结构的控制。本项目将研究水、催化剂孔结构、碳水化合物和产品之间相互作用的基础科学，使用高分辨率测量技术来探索这些材料的分子相互作用。研究结果可能会为如何调整催化过程以在更短的时间内获得更高的产率和产品的选择性提供建议。通过这项研究，学生们将有机会在太平洋西北国家实验室的环境分子科学实验室接受高级培训。这项研究的总体目标是了解水、生物质衍生碳水化合物和呋喃类产品在多孔催化剂中的相互作用。大量生产碳基燃料和化学品所需规模的木质纤维生物质的使用，很可能需要在许多化学转化步骤中使用非均相催化剂进行连续的液相处理。反应介质的各种成分，包括溶剂、反应物、中间体和产物，将在多孔催化剂材料中分配。根据对有机溶剂与水结合的混合溶剂体系中显著影响的观察，假设分子在孔隙中的不同吸收和它们在孔壁上的特定吸附对选择性有深远的影响。为了在分子水平上阐明界面限制的性质并量化这些相互作用的程度，该研究将使用非原位和原位固体核磁共振(NMR)监测固-液界面，通过使用专门设计的高温-高压魔角旋转探针来评估碳水化合物衍生分子的局部结构及其在沸石、介孔二氧化硅、有机硅和碳等多孔材料中的变化率。这些信息将与探测吸收/吸附现象的热力学的量热测量和探索其动力学的重量测量相结合。作为这项研究的一部分，学生将通过太平洋西北国家实验室的环境分子科学实验室接受先进的核磁共振技术培训。对界面受限物种行为的了解将识别为反应物选择的孔结构，促进所需的反应，并排出特定的所需产物，如呋喃。

PI Name: Susannah L. ScottProposal Number: 1512228The sustainable production of important chemicals and fuels at large scale can be achieved by using renewable resources such as non-food biomass. The selective conversion of biomass-derived carbohydrates to specific chemicals in liquid water using porous solid catalysts is controlled in part by the molecular movement of biomass derived carbohydrate molecules into the porous structure of the catalyst, as well as the movement of products out of the porous structure. This project will study the fundamental science underlying the interactions between water, catalyst pore structure, carbohydrates, and products using high resolution measurement techniques which probe the molecular interactions of these materials. The outcomes of the research may suggest ways to adjust the catalysis process to achieve higher yield and selectivity of products in shorter times. Through this research, students will be given opportunities for advanced training at the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory.The overall goal of this research is to understand the interactions between water, biomass-derived carbohydrates, and furan-based products within porous catalysts. The use of lignocellulosic biomass on the scale required for significant production of carbon-based fuels and chemicals will likely involve continuous liquid-phase processing with heterogeneous catalysts in many of the chemical conversion steps. Various components of the reaction medium, including solvent, reactants, intermediates and products, will partition within the porous catalyst material. Differential absorption of molecules into the pores and their specific adsorption onto the pore walls are hypothesized to have profound consequences for selectivity, based on observations of dramatic effects in mixed solvent systems where an organic solvent is combined with water. To elucidate the nature of the interface confinement at the molecular level and to quantify the extent of these interactions, the research will use ex-situ and in-situ solid-state nuclear magnetic resonance (NMR) monitoring of solid-liquid interfaces, via the use of specially designed high temperature-high pressure magic-angle-spinning probes, to assess local structures of carbohydrate-derived molecules and their rates of transformations in porous materials such as zeolites, mesoporous silicas and organosilicas, and carbons. This information will be combined with calorimetric measurements that probe the thermodynamics of absorption/adsorption phenomena, and gravimetric measurements to probe their kinetics. As part of this research, students will be trained on advanced NMR techniques through the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory. Knowledge gained on the behavior of interface-confined species will identify pore structures that select for reactants, promote desired reactions and expel specific desired products, such as furanics.