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CAREER: Cation and Nanoparticle Interconversion in Metal-Exchanged Zeolites

职业：金属交换沸石中的阳离子和纳米颗粒相互转化

基本信息

批准号：
2144174
负责人：
Chris Paolucci
金额：
$ 59.73万
依托单位：
University of Virginia Main Campus
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-02-15 至 2027-01-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2144174&HistoricalAwards=false
关键词：
CAREER Cation Nanoparticle Interconversion Metal

项目摘要

Small pore, microcrystalline zeolite materials are widely used in the chemicals and fuels industries for processes where molecular-scale capture, separation, or catalytic reaction is needed. In the case of catalysis, zeolites are often used in conjunction with extremely small particles of catalytic metals – or even individual atoms – dispersed throughout the nanoscale pores and voids in the zeolite structure. The resulting catalysts are highly effective for promoting specific catalytic reactions, while efficiently utilizing small amounts of expensive metals such as platinum or palladium. Nevertheless, the harsh conditions associated with many catalytic reactions results in metal particle agglomeration and concomitant loss of catalyst efficiency. The project develops computational molecular models and theory predicting the dynamics of agglomeration and redispersion of metals supported by zeolites. In addition, the models include design and synthesis features that deter the agglomeration of metal atoms and particles under reaction conditions, thus improving the energy efficiency of catalysts widely used for petrochemical and emissions related applications. The project is integrated with efforts that address retention of underrepresented communities at multiple points in the STEM pipeline, through collaboration with local organizations that emphasize coding for girls in K-12, and by organizing events that address social and professional development challenges faced by both international and domestic undergraduate and graduate engineering students. The project develops atomistic models that describe how zeolite composition, gas conditions, and nanoparticle size and distribution affect the thermodynamics and kinetics of cation and nanoparticle interconversion in zeolites. The main objectives are to 1) model the thermodynamics of zeolite-supported platinum and palladium cation and nanoparticle interconversion, 2) predict how catalytically relevant reactant gases promote or impede interconversion, 3) determine how zeolite encapsulation modulates the structure and energy of nanoparticles, and 4) determine the fundamental processes that govern the kinetics of interconversion between cations and nanoparticles. These objectives will be fulfilled by using molecular modeling tools that include density functional theory, wave function theory, classical forcefields, and Monte Carlo simulations. This project will provide guidance on the engineering of deactivation resistant zeolites, a challenge at the frontiers of catalysis and zeolite synthesis. Further, the project will enable transformative predictions of zeolite compositions and synthetic strategies that stabilize catalyst performance in the reaction environment.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

小孔、微晶沸石材料广泛用于需要分子规模捕获、分离或催化反应的化工和燃料行业。在催化方面，沸石通常与极小的催化金属颗粒--甚至单个原子--一起使用，分散在沸石结构中的纳米级孔隙和空隙中。生成的催化剂在促进特定催化反应方面非常有效，同时有效地利用了少量昂贵的金属，如铂或钯。然而，与许多催化反应相关的苛刻条件导致了金属颗粒的团聚和伴随而来的催化剂效率的损失。该项目开发了预测沸石支持的金属团聚和再分散动力学的计算分子模型和理论。此外，这些模型还包括设计和合成功能，可在反应条件下阻止金属原子和颗粒的团聚，从而提高广泛用于石化和排放相关应用的催化剂的能效。该项目与在STEM管道的多个点保留代表性不足的社区的努力相结合，方法是与强调为K-12女孩编码的当地组织合作，并组织活动，解决国际和国内本科生和工程学研究生面临的社会和职业发展挑战。该项目开发了描述沸石组成、气体条件以及纳米颗粒大小和分布如何影响沸石中阳离子和纳米颗粒相互转化的热力学和动力学的原子模型。主要目的是1)模拟沸石负载的铂、钯离子和纳米颗粒相互转化的热力学，2)预测催化相关的反应气体如何促进或阻碍相互转化，3)确定沸石包裹如何调节纳米颗粒的结构和能量，以及4)确定支配阳离子和纳米颗粒之间相互转化动力学的基本过程。这些目标将通过使用包括密度泛函理论、波函数理论、经典力场和蒙特卡罗模拟在内的分子模拟工具来实现。该项目将为抗失活沸石的工程设计提供指导，这是催化和沸石合成的前沿挑战。此外，该项目将能够对沸石成分和合成策略进行变革性的预测，以稳定反应环境中的催化剂性能。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。