(309a) Designing Multifunctional Zeolites for Improved Catalytic Performance

A common objective of zeolite catalyst design is to overcome the inherent mass transport limitations of nanopores, often through the design of nanosized or hierarchical materials¹; however, the complex pathways of zeolite crystallization make it difficult to control their physicochemical properties.² This talk will describe recent approaches of seeding and interzeolite transformation as versatile methods to achieve optimal materials, including the synthesis of self-pillared³, finned⁴, zoned⁵, and coreshell⁶ zeolites, which exhibit exceptional catalytic performance compared to conventional analogues. This talk will also highlight our collaboration with Mike Harold on a project involving the design of an ammonia slip catalyst (ASC) using a dual-layer architecture composed of Pt/Al₂O₃ (PGM) and metal (Fe, Cu)-exchanged zeolite (M-Z) layers.⁷ In our collaborative project, we scaled the dual-layer concept down to the level of a single coreshell (CS) catalyst particle, Pt/Al₂O₃@Cu/ZSM-5, composed of a PGM core and a M-Z shell. Evaluation of the CS catalyst in a fixed-bed reactor revealed excellent NH₃ oxidation activity and N₂ selectivity. In addition, we obtained an unanticipated enhancement of the Pt/Al₂O₃ performance within the coreshell configuration that gives an exceptional light-off of the NH₃ oxidation. Our findings reveal that the CS catalyst has an equivalent activity to that of a conventional Pt/Al₂O₃ catalyst containing 3 times higher Pt loading, and is more resilient to hydrothermal aging compared to conventional counterparts – results that collectively highlight the impact of crystal engineering in zeolite catalysis.

References:

1. Mallette et al., Nature Synthesis 1 (2022), 521-534
2. Mallette et al., Chemical Reviews 124 (2024) 3416-3493
3. Jain et al., Advanced Materials 33 (2021) 2100897
4. Dai et al., Nature Materials 19 (2020) 1074-1080
5. Le et al., Nature Catalysis 6 (2023) 254-265
6. Le et al., Journal of Catalysis 405 (2022) 664-675
7. Ghosh et al., ACS Catalysis 10 (2020) 3604-3617