Direct propane dehydrogenation (PDH) to propylene is a desirable commercial reaction but is highly endothermic and severely limited by thermodynamic equilibrium. Oxidative routes that oxidatively remove hydrogen as water have safety and cost challenges. We couple chemical looping selective H
2
combustion and PDH with multifunctional FeVO
4
-VO
x
redox catalysts. Well-dispersed VO
x
supported on Al
2
O
3
provides dehydrogenation sites, and adjacent nanoscale FeVO
4
acts as oxygen carriers for subsequent H
2
combustion. We achieve an integral performance of 81.3% propylene selectivity at 42.7% propane conversion at 550°C for 200 chemical looping cycles for re-oxidizing FeVO
4
. Based on catalytic experiments, spectroscopic characterization, and theory calculations, we propose a hydrogen spillover-mediated coupling mechanism. The hydrogen species generated at the VO
x
sites migrated to adjacent FeVO
4
for combustion, which shifted PDH toward propylene. This mechanism is favored by the proximity between catalytic and combustion sites.
Understanding the structure–activity relationship of surface lattice oxygen is critical but challenging to design efficient redox catalysts. This paper describes data‐driven redox activity descriptors on doped vanadium oxides combining density functional theory and interpretable machine learning. We corroborate that the p‐band center is the most crucial feature for the activity. Besides, some features from the coordination environment, including unoccupied d‐band center, s‐ and d‐band fillings, also play important roles in tuning the oxygen activity. Further analysis reveals that data‐driven descriptors could decode more information about electron transfer during the redox process. Based on the descriptors, we report that atomic Re‐ and W‐doping could inhibit over‐oxidation in the chemical looping oxidative dehydrogenation of propane, which is verified by subsequent experiments and calculations. This work sheds light on the structure–activity relationship of lattice oxygen for the rational design of redox catalysts.
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 MoO3-Fe2O3 redox catalysts for promoted propylene production. Atomically dispersed Mo species over γ-Fe2O3 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-Fe2O3 to Fe3O4 contribute to selectively oxidative dehydrogenation instead of over-oxidation in pristine γ-Fe2O3. 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.
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