CO2 as a soft oxidant for propane oxidative dehydrogenation: A mechanistic study using operando UV Raman spectroscopy

Unraveling the Active Vanadium Sites and Adsorbate Dynamics in VOx/CeO2 Oxidation Catalysts Using Transient IR Spectroscopy

“…Exposure to ODH conditions leads to an intensity decrease of the Ce–O surface phonon at 405 cm –1 as well as the features within the range of 470–600 cm –1 assigned to the defect region, containing a contribution of Ce 3+ at 550 cm –1 and oxygen vacancies at 590 cm –1 . , This behavior indicates surface reduction of ceria, whereby lattice oxygen is used to oxidize propane to propylene and CO x . Note that ceria, as an active support material, clearly participates in the reaction, in contrast to other carriers, such as SiO 2 . , Interestingly, the vanadia structures (V–O–Ce, V–O–V, V=O) seem to remain unchanged during the reaction, as no observable intensity changes are detected between oxidative and reactive conditions, which is consistent with the previously mentioned literature but appears to be at odds with the d–d transitions observed in the UV–vis spectra.…”

“…Note that ceria, as an active support material, clearly participates in the reaction, in contrast to other carriers, such as SiO 2 . 61,62 Interestingly, the vanadia structures (V−O−Ce, V− O−V, V=O) seem to remain unchanged during the reaction, as no observable intensity changes are detected between oxidative and reactive conditions, which is consistent with the previously mentioned literature but appears to be at odds with the d−d transitions observed in the UV−vis spectra.…”

Research progress of CO2 oxidative dehydrogenation of propane to propylene over Cr-free metal catalysts

“…-O-V 3? sites and CO. A similar pathway was confirmed by Hess et al using operando UV Raman spectroscopy [84,85]. They observed distinct changes of the surface V species involving the breakage of V-O-V bonds, a partial reduction in vanadyl, as well as the formation of support hydroxyl groups.…”

A critical evaluation of the catalytic role of CO2 in propane dehydrogenation catalyzed by chromium oxide from a DFT-based microkinetic simulation

“…Among soft oxidants, CO 2 is the most widely examined one. 10,[12][13][14] The use of CO 2 as an oxidant not only improves the catalytic performance but also reduces the greenhouse gas emissions. Therefore, it is a win-win solution.…”