Unraveling the structure-activity relationship in propane dehydrogenation: Hybridly-constructed atomically-dispersed Co2+ vs. Impregnated Co3O4 clusters on alumina

For propane dehydrogenation (PDH), cobalt-based catalysts are attractive candidates to replace Pt- and Cr-based systems, yet their practical application is hindered by rapid deactivation through sintering and coke deposition. In this work, we report a hybrid synthesis strategy to fabricate a Co–Al 2 O 3 catalyst (Co-Al 2 O 3 -INC) with atomically-dispersed Co 2+ sites strongly anchored in the γ-Al 2 O 3 . In contrast to an impregnated catalyst (Co-Al 2 O 3 -IMP) that forms reducible Co 3 O 4 clusters and suffers severe deactivation, the Co-Al 2 O 3 -INC catalyst exhibits high stability with propane conversion decreasing only marginally from 27.8% to 23.5% over 5 h. Extensive characterization confirms that the atomic dispersion of tetrahedral Co 2+ sites and the resulting strong metal–support interaction effectively suppress cobalt reduction and sintering, leading to significantly reduced coke formation. This study underscores the critical role of stabilizing isolated active sites via tailored synthesis for achieving highly stable PDH catalysts.