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

Abstract

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 CoOx 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.