Dynamic Monte Carlo and Molecular Dynamics Simulations of Transport Catalytic Materials

将对柱撑粘土中的扩散和吸附过程进行系统的蒙特卡罗和分子动力学模拟研究。柱撑粘土是一种新型的催化材料，在化学上类似于沸石，但在形态上与沸石非常不同。沸石一直是广泛的实验和理论研究的对象，而对柱撑粘土的研究主要是实验性的。与沸石相比，柱撑粘土具有更大的结构灵活性，即通过改变柱子的高度、大小和分布，柱撑粘土的结构可以针对特定的反应和/或分离应用进行优化。因此，为了充分利用这种结构灵活性，重要的是要了解柱撑粘土的基本热力学和传输性质及其对物理化学特性的依赖，以及通过多孔介质扩散的分子物种的依赖关系。这项工作将系统地研究以下内容：1.三维分子在不同尺寸、高度和柱状分布的柱撑粘土中的扩散。2.低流量(或高密度)下具有可逆和不可逆吸附的扩散。3.扩散和吸附随分子间作用力和表面力以及扩散分子的形状、大小和柔韧性的变化。4.比较蒙特卡罗和分子动力学的结果，建立MC模拟时间和MD时间之间的关系(如果有)。5.多组分在多孔介质中的扩散研究及互扩散系数的估算。

Systematic Monte Carlo and Molecular Dynamics simulation studies for diffusion and sorption processes in pillared-clays will be conducted. Pillared clays are a new class of catalytic material chemically similar to, but morphologically very different from, zeolites. Zeolites have been the subject of extensive experimental and theoretical studies while studies on the pillared clays are primarily experimental. Compared to zeolites, pillared-clays have the advantage of having more structural flexibility, that is, by changing the height, size and distribution of the pillars the structure of the pillared-clay can be optimized for particular reaction and/or separation applications. As a result, in order to fully exploit this structural flexibility, it is important to understand the fundamental thermodynamic and transport properties and their dependence on the physicochemical characteristics of the pillared-clays, as well as those of the molecular species diffusing through the porous medium. This work will systematically examine the following: 1. Diffusion of 3-Dimensional molecules through pillared- clay of various size, height and distribution of pillars. 2. Diffusion with reversible and irreversible adsorption at low and high flow rates (or densities). 3. The variation of diffusion and sorption with inter- molecular and surface forces and with the shape, size and flexibility of the diffusing molecules. 4. Comparison of Monte Carlo and Molecular Dynamics results to establish the relationship between MC simulation time and MD time, if any. 5. Studies of multicomponent diffusion in porous media and the evaluation of mutual diffusivities.