BRIGE: Tailoring Zeolite Crystallization Through Molecular Design

1032621 rimerr .在材料设计中，开发合理的策略来先验地调整有序材料的自组装，并具有可预测的结构结果是一个巨大的挑战，其中很少有固态材料的合成方案可以系统地和精确地操纵晶体习惯。在沸石合成中，精确控制晶体尺寸和形态的工程路线是解决系统设计限制的基准，这些限制可能会使其在商业应用中的性能和经济可行性边缘化。ZSM-5是一种普遍存在的沸石催化剂，它是在对结晶知之甚少的情况下通过经验合成的，本研究计划的目的是制定一种合理的设计策略来操纵ZSM-5的生长。该bridge提案将利用PI在晶体工程和表面科学方面的专业知识，在界面水平上研究ZSM-5结晶，使用原子力显微镜执行以下任务：(i)开创各向异性生长动力学的原位测量；（ii）开发一种设计策略，使用具有分子识别的定制修饰剂来结合特定的晶体表面并调节生长；（iii）实时监测生长动态，以揭示自组装的潜在机制，这将有助于开发调整晶体习惯的预测模型。ZSM-5由于其高活性的氮氧化物还原，是一种很有前途的温室气体排放技术催化剂。对ZSM-5晶体习性的合理修饰可以改变其孔表面积和内部扩散路径长度，从而调控催化活性。事实上，最近的研究表明，超薄的ZSM-5血小板，这是难以实现的传统合成，具有显着的更高的收率，选择性和寿命。本研究计划目标的成功完成将为沸石合成提供一种变革性的方法，并为设计提供启发式指南，具有潜在的更广泛的适用性，可用于无机材料在能源和选择性分离领域的可行应用。该研究项目的长期目标是建立一个综合平台，设计、建模和测试用于NOx选择性催化还原（SCR）的沸石，利用甲烷进行车载SCR技术开发。提议活动的智力价值：这项提议的研究将推进我们对沸石结晶的基本理解，利用PI在晶体工程方面的专业知识，以沸石科学中尚未利用的方式应用AFM -即原位生长测量来系统地量化各向异性动力学，以及力测量来探测分子识别和晶体界面的结合。ZSM-5的分子设计原理将成为解决更广泛的沸石结构的平台，提供前所未有的晶体特性控制，这是传统方法无法实现的。长期计划将与休斯敦大学德克萨斯柴油测试和研究中心（TDTRC）的教师建立协同合作，设计和优化用于NOx CH4-SCR的沸石。拟议活动的更广泛影响：该bridge赠款将帮助在K-12，本科和博士阶段建立一个推广计划，以促进工程教育和研究，重点是通过休斯敦大学的PROMES和LSAMP计划，少数民族和女性学生（其少数民族入学率在全国研究型大学中排名第二）。该计划将通过实践经验和课堂讲座来促进主动学习，使用结晶中的概念来吸引学生对科学的兴趣，并提高对工程职业中跨学科机会的认识。PI将与KIPP休斯顿高中（全国大学准备排名第16位的少数族裔机构）合作，在PI的实验室建立一个学生和教师的动态项目（NSF-RET）研究，并定期在KIPP的AP化学课上进行客座讲座。PI将指导NSF-REU， UH的本科生和研究生的研究，使用这些研究的结果作为胶体选修课程的综合主题。

1032621RimerDeveloping rational strategies for a priori tuning the self-assembly of ordered materials with predictable structural outcomes is a grand challenge in materials design, wherein few synthetic schemes of solid state materials are amenable to systematic and precise manipulation of crystal habit. In zeolite synthesis, engineering facile routes to precisely control crystal size and morphology is a benchmark for addressing systemic design limitations, which can marginalize their performance and economic viability in commercial applications. The objective of this proposed research plan is to develop a rational design strategy for manipulating the growth of ZSM-5, a ubiquitous zeolite catalyst, which is synthesized empirically with little fundamental understanding of crystallization. This BRIGE proposal will leverage the PI's expertise in crystal engineering and surface science to investigate ZSM-5 crystallization at an interfacial level, using atomic force microscopy to perform the following tasks: (i) pioneer in situ measurements of anisotropic growth kinetics; (ii) develop a design strategy using tailored modifiers with molecular recognition for binding to specific crystal faces and mediating growth; and (iii) monitor growth dynamics in real time to uncover the underlying mechanisms of self-assembly, which will facilitate the development of predictive models for tuning crystal habit. ZSM-5 is a promising catalyst for greenhouse gas emissions technologies due to its high activity for NOx reduction. The judicious modification of ZSM-5 crystal habit can alter porous surface area and internal diffusion pathlength, which regulate catalytic activity. Indeed, recent studies reveal that ultrathin ZSM-5 platelets, which are difficult to achieve by conventional syntheses, exhibit notably higher yield, selectivity, and lifetime. The successful completion of objectives in this research plan will provide a transformative approach to zeolite synthesis, and heuristic guidelines for design with potentially broader applicability to inorganic materials for viable applications in areas of energy and selective separations. The long-term trajectory of this research program aims to establish a comprehensive platform to design, model, and test zeolites for selective catalytic reduction (SCR) of NOx, using methane for on-board vehicle SCR technology development.Intellectual merit of the proposed activities: This proposed research will advance our fundamental understanding of zeolite crystallization, capitalizing on the PI's expertise in crystal engineering to apply AFM in ways that have not been utilized in zeolite science - namely in situ growth measurements to systematically quantify anisotropic kinetics, and force measurements to probe molecular recognition and binding at crystal interfaces. Molecular design principles of ZSM-5 will become a platform for addressing a broader range of zeolite structures, offering unprecedented control of crystal properties, which are unattainable by conventional methods. Long-term initiatives will institute synergistic collaborations with faculty at UH's Texas Diesel Testing and Research Center (TDTRC) to design and optimize zeolites for NOx CH4-SCR.Broader impact of the proposed activities: This BRIGE grant will help establish an outreach program at the K-12, undergraduate, and Ph.D. levels to promote engineering education and research, with emphasis on minority and female students through the PROMES and LSAMP programs at UH (whose minority enrollment ranks 2nd among national research universities). This plan will foster active learning through hands-on experience and classroom lectures, using concepts in crystallization to engage student interest in the sciences and increase awareness of interdisciplinary opportunities in engineering careers. The PI will partner with KIPP Houston High School (a minority institution ranked 16th in national college readiness) to establish a dynamic program for student and teacher (NSF-RET) research in the PI's lab and periodic guest lectures in KIPP's AP chemistry class. The PI will mentor NSF-REU, UH undergraduate and graduate research, using results of these studies as integrated topics in a colloids elective course.