LEAPS-MPS: Elucidating the Role of Seed Chemical Composition in Interzeolite Transformation Synthesis

About This Grant

Non-Technical Summary Zeolites are materials that are well-known as catalysts and adsorbents for many chemical and fuel manufacturing processes. Despite their commercial use over several decades, there is a continued need to optimize zeolites for better efficiency, new applications, and lower manufacturing costs. Recent studies in the field of zeolite science have focused on their synthesis methods and how they can affect zeolite performance in various applications. This LEAPS-MPS project investigates one particular synthesis technique that has shown promise for preparing new types of zeolites that may offer improved performance over existing materials. The knowledge gained in these studies helps the zeolite synthesis community better understand how to control fundamental synthesis processes to develop enhanced catalytic and adsorptive materials. In addition to the technical knowledge, this work addresses a significant decline in essential zeolite synthesis research in the United States over the past 30 years - a field of study that was once led by US-based researchers. Finally, the grant helps connect early-career researchers and K-12 and community college students to local issues which could benefit from technological advances resulting from this project. Technical Summary Zeolites' high surface areas, tunability, and stability allow them to be among the best materials for catalyst, adsorption, and ion-exchange uses. However, many applications require further research to bring them to a commercially viable level, and new zeolite frameworks or optimized versions of existing zeolites are required. This LEAPS-MPS project focuses on studying the interzeolite transformation (IZT) method of synthesis, which uses a zeolitic source of silica and alumina (the parent material) to form a different zeolite framework (the child zeolite). Preliminary results show that aluminosilicate parent zeolites in IZT reactions can be seeded with a small amount of a child zeolite seed that contains heteroatoms other than aluminum (M; for example, boron). The resulting child zeolite is an aluminosilicate product with the structure of the M-zeolite seed. However, there is a gap in knowledge surrounding the role of the seed heteroatoms in the seeding process. If zeolite scientists can better comprehend these processes, they can then begin to think about ways to control the syntheses such that they obtain new aluminosilicate zeolites that can compete with existing catalytic and adsorption materials. The approach taken in this work first synthesizes B-, Ga-, Ge-, and SAPO-zeolites as seeds, which are subsequently used in IZT reactions with ultra-stable Y zeolite as the parent zeolite. In addition, a range of heteroatom content in the seeds is studied to understand the influence of silica versus the heteroatoms. Finally, the rate of interzeolite transformation is compared between mixed-chemistry and same-chemistry IZT systems. Catalysis of sustainable feedstocks and local scientific issues that impact those in the San Jose, California metropolitan area are incorporated into educational modules for K-14 students. The goal is for these students to pursue STEM degrees so they can tackle critical scientific topics that affect the very communities from which they come. Finally, this work will help train members of the next generation of zeolite scientists in the United States. 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.