SSZ‐13 Zeolite with Isolated Co$^{2+}$ Sites as an Efficient and Durable Catalyst System for Non‐Oxidative Ethane Dehydrogenation

Non-oxidative dehydrogenation of ethane (EDH) is an attractive method for on-purpose ethene production, but achieving high activity and, especially, durability with catalysts based on earth-abundant metals remains challenging. Herein, we introduce the Co/SSZ-13 system with exclusively divalent cobalt (Co$^{2+}$) ions that meets the above requirements. The use of complementary characterization techniques enabled us to reveal two Cu$^{2+}$ species: Co$^{2+}$─Z$_2$ located in the six-membered-ring windows and [Co(OH)]$^+$─Z in the eight-membered-ring windows, with Z representing a charged zeolite framework site. A quantitative correlation between the rate of ethene formation and the site population establishes Co$^{2+}$─Z$_2$ as the active species. In situ X-ray absorption spectroscopy confirms their structural and electronic stability under high-temperature reaction conditions. The optimized 0.9Co/SSZ-13 (0.9Co) catalyst showed highly durable operation over 200 dehydrogenation/oxidative regeneration cycles at 600–650°C lasting for 150 h with industrially relevant productivity. In this regard, it outperforms almost all previously developed catalysts even those with platinum as an active component. ... mehrThe obtained results uncover the atomic-level origins of EDH activity/durability of the Co/SSZ-13 system and highlight the critical role of metal site location in designing highly active, selective, and durable catalysts for on-purpose ethene production.