Silica-encapsulated Co/BEA core–shell catalysts for PDH: Stabilizing tetrahedral Co2+ and inhibiting coke formation

Propylene is a key chemical. Propane dehydrogenation (PDH) over non-noble cobalt catalysts suffers rapid deactivation from sintering and coking. Herein, we report a core–shell catalyst (1.0Co/BEA@ x Si) with a mesoporous silica shell on Co-impregnated dealuminated Beta zeolite. The silica shell enhances Co dispersion and modulates Co reduction: it promotes the formation of active tetrahedral Co 2+ sites from Co 3 O 4 while suppressing over-reduction to metallic Co 0 . The optimized 1.0Co/BEA@1.0Si maintains ~99% propylene selectivity and achieves a formation rate of 71.0 gC 3 H 6 ·g Co −1 ·h −1 after 980 min, far surpassing uncoated 1.0Co/BEA and most reported Co-based PDH catalysts. In situ and post-reaction analyses show the shell strengthens propane adsorption/activation and reduces coke formation. Core–shell engineering thus stabilizes active metal states via local redox microenvironment modulation, offering new design principles for robust alkane dehydrogenation catalysts.