γ-Al₂O₃ sheet-stabilized isolate Co²⁺ for catalytic propane dehydrogenation

Co-based catalysts are promising alternatives to replace Pt- and Cr-based catalysts for propane dehydrogenation (PDH) in view of the catalytic activity for C–H bond activation, low cost, and low toxicity. However, the reduction of unstable CoO_x species and coke deposition cause serious catalyst deactivation. In this work, a sheet-shaped Co–Al₂O₃ catalyst comprising of isolate Co²⁺ sites shows a high intrinsic activity (specific reaction rate > 16 mmol g⁻¹ h⁻¹) and catalytic stability in highly selective PDH reaction (>97% C₃H₆ selectivity). Extensive characterization demonstrates that the tetrahedral Co²⁺ isolated site is stabilized by the γ-Al₂O₃ matrix, facilitating propylene desorption to inhibit formation of coke and other byproducts and to free the active Co sites.