Concerted oxygen diffusion across heterogeneous oxide interfaces for intensified propane dehydrogenation

Non-oxidative dehydrogenation technologies suffer from the thermodynamic equilibrium limitations and severe coking. Here, the authors report the intensified propane dehydrogenation to propylene by the chemical looping engineering on nanoscale core-shell redox catalysts. Propane dehydrogenation (PDH) is an industrial technology for direct propylene production which has received extensive attention in recent years. Nevertheless, existing non-oxidative dehydrogenation technologies still suffer from the thermodynamic equilibrium limitations and severe coking. Here, we develop the intensified propane dehydrogenation to propylene by the chemical looping engineering on nanoscale core-shell redox catalysts. The core-shell redox catalyst combines dehydrogenation catalyst and solid oxygen carrier at one particle, preferably compose of two to three atomic layer-type vanadia coating ceria nanodomains. The highest 93.5% propylene selectivity is obtained, sustaining 43.6% propylene yield under 300 long-term dehydrogenation-oxidation cycles, which outperforms an analog of industrially relevant K-CrOx/Al2O3 catalysts and exhibits 45% energy savings in the scale-up of chemical looping scheme. Combining in situ spectroscopies, kinetics, and theoretical calculation, an intrinsically dynamic lattice oxygen donator-acceptor process is proposed that O2- generated from the ceria oxygen carrier is boosted to diffuse and transfer to vanadia dehydrogenation sites via a concerted hopping pathway at the interface, stabilizing surface vanadia with moderate oxygen coverage at pseudo steady state for selective dehydrogenation without significant overoxidation or cracking.

Automated summary

The intensified propane dehydrogenation to propylene by chemical looping engineering on nanoscale core-shell redox catalysts achieves a propylene selectivity of 93.5% and a propylene yield of 43.6%, outperforming traditional oxidation-reduction catalysts and offering higher energy efficiency.