Regulating lattice oxygen mobility of FeOx redox catalyst via W-doping for enhanced chemical looping oxidative dehydrogenation of ethane

Abstract

The precise regulation of lattice oxygen mobility toward matched surface reaction kinetics is the key issue for rational design of chemical looing oxygen carriers. Herein, we successfully regulated lattice oxygen reactivity of FeOx redox catalyst via a W-doping strategy to realize efficient chemical looping oxidative dehydrogenation (CL-ODH) of ethane to ethylene. Specifically, the addition of W could significantly increase the binding energy of Fe-O bond, inhibiting the over-quick lattice oxygen migration toward over-oxidation. On this basis, the mild reduction of active Fe3O4 and slowly released oxygen ions involving in dehydrogenation at a matched kinetic rate could greatly prolong the active period, leading to a record high ethane processing capacity (120 ml·gcat−1·cycle−1) and productivity of ethylene (selectivity ∼83 %) during continuous dehydrogenation-regeneration cycles. This work provides a highly active CL-ODH catalyst and new insight into metal oxide redox chemistry.