Coupling acid catalysis and selective oxidation over MoO 3 -Fe 2 O 3 for chemical looping oxidative dehydrogenation of propane.

Redox catalysts play a vital role in chemical looping oxidative dehydrogenation processes, which have recently been considered to be a promising prospect for propylene production. This work describes the coupling of surface acid catalysis and selective oxidation from lattice oxygen over MoO 3 -Fe 2 O 3 redox catalysts for promoted propylene production. Atomically dispersed Mo species over γ-Fe 2 O 3 introduce effective acid sites for the promotion of propane conversion. In addition, Mo could also regulate the lattice oxygen activity, which makes the oxygen species from the reduction of γ-Fe 2 O 3 to Fe 3 O 4 contribute to selectively oxidative dehydrogenation instead of over-oxidation in pristine γ-Fe 2 O 3 . The enhanced surface acidity, coupled with proper lattice oxygen activity, leads to a higher surface reaction rate and moderate oxygen diffusion rate. Consequently, this coupling strategy achieves a robust performance with 49% of propane conversion and 90% of propylene selectivity for at least 300 redox cycles and ultimately demonstrates a potential design strategy for more advanced redox catalysts.