| NSF Org: |
CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems |
| Recipient: |
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| Initial Amendment Date: | August 31, 2016 |
| Latest Amendment Date: | August 31, 2016 |
| Award Number: | 1628960 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Robert McCabe
CBET Division of Chemical, Bioengineering, Environmental, and Transport Systems ENG Directorate for Engineering |
| Start Date: | September 1, 2016 |
| End Date: | August 31, 2020 (Estimated) |
| Total Intended Award Amount: | $330,430.00 |
| Total Awarded Amount to Date: | $330,430.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
201 OLD MAIN UNIVERSITY PARK PA US 16802-1503 (814)865-1372 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
Fenske Laboratory University Park PA US 16802-4400 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | DMREF |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.041 |
ABSTRACT
1629398/1628960
Palmer, Jeremy/Rioux, Robert M.
The project addresses improved designs of crystalline zeolite materials used in applications ranging from catalysis and energy storage to electronics design. The nanometer sized pores of the zeolite materials are ideally suited for a wide range of separations and selective catalytic conversions in the chemical and petroleum industries. A promising strategy for improving the properties of zeolites is to tune crystal shape and size using targeted synthetic approaches. The overall goal of this project is to develop computer simulation methods for rapidly identifying small-molecule compounds known as growth modifiers that can be used to control zeolite crystal shape and size. This will accelerate the development of new catalysts, adsorbents, and separations materials for converting inexpensive and abundant sources of natural gas into fuels and high-valued compounds while simultaneously lowering toxic emissions.
A technique that is broadly utilized in both natural and synthetic crystallization to control crystal habit and morphology is the use of modifiers, which are molecular (or macromolecular) additives that possess an affinity for selectively adsorbing on specific crystal faces and altering the anisotropic rate(s) of growth. The most critical challenge in this field of research, irrespective of the material and application, is the incomplete understanding of the molecular-level interactions and thermodynamic driving forces that govern the adsorption and binding specificity of modifiers to different crystal surfaces. The focus of this project is to integrate zeolite synthesis, characterization, and modeling to develop an experimentally-validated computational platform for characterizing growth modifier effects on crystallization based on equilibrium adsorption properties. This will be achieved by addressing three specific aims: (1) develop, validate, and iteratively refine density functional theory and molecular simulation models for predicting modifier adsorption using experimental benchmark data; (2) assess model predictability and transferability to other modifier-zeolite systems; and (3) elucidate structure-property relationships as a means of establishing guidelines for modifier selection. This computational platform will improve our understanding of the mechanisms governing modifier efficacy and specificity, thereby providing a foundation for identifying effective modifiers and potentially accelerating their discovery by two orders of magnitude. The fundamental knowledge gained from this project will serve as a translational guide for the rational design of growth modifiers, fostering the development of improved strategies for controlling crystallization processes relevant to applications ranging from catalysis to separations and adsorption. The project will also provide educational and outreach components to K-12 students and undergraduates, including opportunities for Houston-area high school students to build molecular zeolite models.
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The primary goal of the project is to use a combination of experiment and simulation to identify potent crystal growth modifiers (CGMs) for tailoring zeolite catalysts. Zeolite catalysts are workhorse of chemical conversion in the modern-day refinery. However, the intrinsic structure of zeolite, both interparticle and intraparticle are not necessarily optimized for the most active and selective conversion. In this DMREF project, we focus on intraparticle aspects of zeolites and how small molecule modifiers can be used to control the aspect ratio and crystallographic orientation of zeolite crystals. Zeolites tend to form highly anisotropic crystals with their pores oriented along the longest dimension of the crystal, such that access to exterior pore openings is restricted to low surface area crystal facets. This synthetic design challenge can be addressed using CGMs, which are molecular additives that adsorb on specific crystal faces and alter anisotropic rate(s) of growth. The control over rates of growth facilitated by CGMs allow crystal size and shape to be controlled during synthesis, producing high performance materials with transformative physiochemical properties. The key challenges with this approach, however, are developing fundamental understanding of why some CGMs are more potent than others and developing methods for identifying potent CMGs a priori, thereby obviating the need to perform costly and time-consuming experimental screening studies. During the lifetime of this proposal, researchers at the University of Houston in collaboration with researchers at the Pennsylvania State University have developed and applied experimentally validated physics-based computational approaches to study CGM adsorption on zeolites. A key objective of this DMREF proposal is understanding the impact of organic-zeolite interactions on zeolite morphology and how zeolite morphology in turn influences material performance characteristics. We have demonstrated that exfoliated and finned zeolites provide physical dimensions that enhance catalysis. In this project, we have demonstrated the CGM strategy to guide interparticle morphology is general across many zeotypes, and the development of theory and simulation to enable apriori design of zeolite crystal morphology while challenging due to the weak interactions and complex interplay amongst constituents in a zeolite synthesis, but critical to optimize zeolite syntheses for targeted applications.
Last Modified: 01/05/2021
Modified by: Robert M Rioux
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