Oxygen chemistry plays a pivotal role in numerous chemical reactions. In particular, selective cleavage of C–H bonds by metal oxo species is highly desirable in dehydrogenation of light alkanes. However, high selectivity of alkene is usually hampered through consecutive oxygenation reactions in a conventional oxidative dehydrogenation (ODH) scheme. Herein, we show that dual-functional Mo–V–O mixed oxides selectively convert propane to propylene via an alternative chemical looping oxidative dehydrogenation (CL-ODH) approach. At 500 °C, we obtain 89% propylene selectivity at 36% propane conversion over 100 dehydrogenation–regeneration cycles. We attribute such high propylene yieldwhich exceeds that of previously reported ODH catalyststo the involvement and precise modulation of bulk lattice oxygen via atomic-scale doping of Mo and show that increasing the binding energy of V–O bonds is critical to enhance the selectivity of propylene. This work provides the fundamental understanding of metal–oxygen chemistry and a promising strategy for alkane dehydrogenation.

Supported vanadium oxides are one of the most promising alternative catalysts for propane dehydrogenation (PDH) and efforts have been made to improve its catalytic performance. However, unlike Pt-based catalysts, the nature of the active site and surface structure of the supported vanadium catalysts under reductive reaction conditions still remain elusive. This paper describes the surface structure and the important role of surface-bound hydroxyl groups on VO / γ-Al O catalysts under reaction conditions employing in situ DRIFTS experiments and DFT calculations. It is shown that hydroxyl groups on the VO /Al O catalyst (V-OH) are produced under H pre-reduction, and the catalytic performance for PDH is closely connected to the concentration of V-OH species on the catalyst. The hydroxyl groups are found to improve the catalyst that leads to better stability by suppressing the coke deposition.

Construction of ion nanochannels by entrapping an in situ assembled ion-conductive poly(ionic liquid) in the highly ordered interconnected pores of MOFs.

Supported vanadium oxides serve as a substitutional catalyst for both propane nonoxidative dehydrogenation (PDH) and oxidative dehydrogenation (ODH), resulting from their substantial activity, propene selectivity, and regeneration rate. However, the nature of the active sites under reaction conditions is still under debate. This paper describes the structure–performance relationships of supported vanadium oxides at different degrees of polymerization by combined density function theory (DFT) and experimental studies. We found that when we expose the vanadium oxides to the pure propane gas, the reaction process can be divided into two periods: the initial oxidative dehydrogenation (ODH) dominant period and subsequent nonoxidative dehydrogenation (PDH) dominant period. In the ODH dominant period, the vanadium oxides tend to lose the top oxygen (VO), while in the PDH dominant period, the vanadium oxides are relatively stable. Electronic structure analysis indicates that the oxygen p-band center correlates with the dehydrogenation barrier on the oxygen site, which is useful to predict its dehydrogenation activity.