ZnNbO catalysts for propylene production via catalytic dehydrogenation of propane
•ZnNbO oxides are efficient in propane dehydrogenation to propylene.•ZnNb2O6 is the active site for propane dehydrogenation.•Surface ZnO species enhance the adsorption capacity of propane.•Coke deposition is the reason for the catalyst's reversible deactivation.•The loss of ZnO to form Zn3Nb2O8 causes the catalyst's irreversible deactivation.
ZnNbO oxides were proved to be highly active and selective in catalytic dehydrogenation of propane to propylene. The optimal results, 28.1 wt.% propylene yield and 84% selectivity were achieved over the sample calcined at 600 °C with 3.0 molar ratio of ZnO/Nb2O5. XRD, SEM, XPS, and on-line MS results demonstrated a synergetic effect between ZnO and ZnNb2O6 in propane dehydrogenation; ZnNb2O6 was the active site for dehydrogenation reaction. The formation of coke deposition contributed to the fast reversible deactivation while the loss of ZnO species leading to the formation of Zn3Nb2O8 was the reason for the irreversible deactivation of the catalyst.
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Journal: Catalysis Communications - Volume 50, 5 May 2014, Pages 73–77