Studies on the Conversion of FAU Zeolites to SSZ-13: The Rate Advantage of Having Both Si and Al in the FAU Reagent
Abstract
Use of FAU zeolite to form other zeolites (IZC) with the use of an organic structure directing agent (OSDA) has gained great traction. Here we show that the use of a reagent (CBV-720, a high silica dealuminated FAU from Zeolyst) with both the Al and Si atoms in a lattice, and at an ideal Si/Al ratio, greatly enhances the rate of conversion to SSZ-13 (CHA structure). In the course of the studies, we explored the comparison of static, tumbling, and stirred reactors. We also saw that there was a temperature dependence where the best reaction condition, OSDA I and CBV-720, works at 95 °C but a number of other OSDA and reagents do not. The degradation of CBV-720 to an amorphous phase also still transforms just as rapidly as the intact structure. Because ion exchange was thought to be potentially a key nucleation factor, seeing that the degraded (amorphous) material had lower ion exchange was just as effective reduced the importance of this step. Experiments with an inhibiting OSDA (VI) showed that conversion could be slowed in the best reaction systems and completely stopped in some others. The inhibition appears to function at the nucleation stage.
Copyright and License
© 2023 American Chemical Society.
Acknowledgement
The authors thank Chevron Energy Technology Co. for support and encouragement and for providing an internship for Ricem Diaz Arroyo. We thank Prof. Raj Gounder, Purdue University, for a useful discussion.
Our contribution is part of a special issue to honor Prof. Svetlana Mintova, one of the preeminent researchers in zeolite science. Her career has covered a remarkable amount of ground in her time as a researcher, and she is now a key head of a very strong research effort at the University of Caen in France. She and her collaborators have built a widely recognized and respected center for zeolite science, being particularly strong contributors to the studies of zeolite synthesis with a focus on chemistry of great interest to the industrial users of zeolite materials (which is a remarkably high impact area given the use of zeolites as catalysts for refining, petrochemicals, conversion of new feedstocks to various products and catalysts for environmental pollution control as principal uses). Then the lab is also an important pioneer and contributor to the characterization of zeolite materials through sophisticated approaches in the use of FTIR spectroscopy, as well as other physical chemistry tools. And there is the contribution to the fundamentals of catalysis. One of us (S.I.Z.) has known Prof. Mintova a number of years and has always enjoyed hearing what she is developing that is new to science. But I also want to add a very fun event I got to enjoy as a result of my visiting the lab in 2018. After I had given a lecture in the afternoon, we went out with a number of the students to enjoy refreshments and watch the semifinal game for France en route to its winning the whole World Cup that year. We were driven home that night by one of the students, who skillfully navigated the streets while happy revelers pounded on our car and yelled at us. It was a special experience to be there for this moment of happy delirium.
Contributions
The manuscript was written through contributions of all authors.
Funding
This work was funded by Chevron Energy Technology Co.
Conflict of Interest
The authors declare no competing financial interest.
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Additional details
Identifiers
- ISSN
- 1528-7505
Related works
- Is supplemented by
- https://pubs.acs.org/doi/suppl/10.1021/acs.cgd.3c00219/suppl_file/cg3c00219_si_001.pdf (URL)
Funding
- Chevron (United States)