Elucidating the Role of CO 2 in the Soft Oxidative Dehydrogenation of Propane over Ceria-Based Catalysts

Zeńczak-Tomera

Journal of CO2 Utilization

et al. 2020

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Section: Catalytic Performancementioning

confidence: 69%

“…Many different catalysts were investigated in CO 2 -PDH containing Pt [3], Ni-Fe [4] Cr [5][6][7][8][9][10][11][12][13][14][15][16], Ga [17][18][19][20], In-Al [21][22][23], Fe [24] or V [25,26]. Among them, the chromium oxide-based materials are considered as a very promising for CO 2 -PDH due to high activity and selectivity.…”

Section: Introductionmentioning

confidence: 99%

Effect of dealumination on the catalytic performance of Cr-containing Beta zeolite in carbon dioxide assisted propane dehydrogenation

Zeńczak-Tomera

Journal of CO2 Utilization

et al. 2020

“…Reaction 1), while pure dehydrogenation leads to H2 as a product (Reaction 3) 7,14,19,21,52 . However, the amount of hydrogen in the reactor effluent is also influenced by the extent of reverse water- In the case where direct dehydrogenation (Reaction 3) is the sole contributor to olefin formation, this ratio is expected to have a value equal to one.…”

Section: Effect Of Support and Active Sites On C2h6 Conversion Pathwaysmentioning

confidence: 99%

“…Additionally, in-situ coke removal via reverse Boudouard 17,19,20 mechanism (Eq. 5) and catalyst re-oxidation by CO2 splitting 17,21 (Eq.…”

Section: Introductionmentioning

confidence: 99%

CO2 Assisted Ethane Oxidative Dehydrogenation over MoO3 and V2O5 Catalysts Supported on Reducible CeO2-TiO2

Nguyen¹,

Celik²,

Tsilomelekis

2020

Preprint

Supported MOx (M= Mo, V) on mixed CeO2-TiO2 were investigated for the oxidative dehydrogenation of ethane (ODHE) using CO2 as a mild oxidant. Raman spectroscopic characterization of the synthesized catalysts under dehydrated conditions suggest that surface MoOx species prefer to anchor on the crystalline domains of TiO2. Upon increasing the amount of CeO2 in the mixed oxide support, an intense and broad band at ~930cm-1 underscored that the prevalent species tend to be polymeric (MoOx)n domains. On the other hand, in the case of VOx catalysts, a gradual shift in the symmetric stretching of the vanadyl (V=O) Raman band with increasing CeO2 content was observed that points at the gradual anchoring of the surface vanadia species on both TiO2 and CeO2 thus highlighting the possible existence of the amorphous VOx to be located at the interface of the two mixed oxides. The catalytic behavior of Mo and V were distinct. As the ceria content in the support increased, MoOx catalysts promoted the ODHE via Mars van Krevelen mechanism while VOx catalysts appeared to favor ethane direct dehydrogenation. Investigation of structure-function relationships via in-situ Raman spectroscopic efforts revealed that adding ceria not only changed the redox properties of the support but also improved those of the deposited metal oxide. We also show that upon incorporation of ceria into the support, CO2 directly participates in the reoxidation of the dispersed MoOx species during catalysis. This effect was distinct from the reaction of CO2 in the reverse water gas shift reaction. Operando Raman spectra revealed that the presence of CO2 enhances the stability of the bridging Mo–O–Mo bond of polymeric molybdena domains, which is proposed to affect the relative contribution of oxidative versus non-oxidative pathways in ethane dehydrogenation.

“…As the dehydrogenation of propane to propylene can generate a great number of hydrogens and the hydrogenation of CO 2 to light olefins needs hydrogen greatly, a promising approach is the coupling of propane with CO 2 to produce propylene, which can not only use the hydrogen but also change the reaction balance of propane dehydrogenation to increase the yield of propylene. Although a few studies on the reaction of propane with CO 2 to produce propylene were reported, CO 2 was only as the oxidant …”

Section: Introductionmentioning

confidence: 99%

Catalytic Performance of In/HZSM‐5 for Coupling Propane with CO₂ to Propylene

et al. 2020

The dehydrogenation of propane to propylene is endothermic reaction will generate hydrogen, while the hydrogenation of CO2 to light olefins is exothermic reaction with hydrogen as reactant. Using the CO2 hydrogenation reaction to consume the hydrogen from the propane dehydrogenation reaction, which is more beneficial to propylene generation. Thus, a promising approach of coupling propane with CO2 to produce propylene was proposed. A simple wetness impregnation method was used to prepare the In/HZSM‐5 composite catalyst for this coupling reaction. It was characterized by means of XRD, SEM, TEM, H2‐TPR, NH3‐TPD, XPS, TG, and N2 isothermal adsorption‐desorption. Effects of indium loading, feed volume ratio of propane to CO2, reaction pressure and temperature on the coupling of propane with CO2 to propylene were investigated in a fixed‐bed reactor. When the mass content of indium is 12%, the feeding volume ratio of propane to CO2 is 1 : 4, the reaction pressure is 0.3 MPa and the reaction temperature is 580 °C, the propylene selectivity is 71.41%, as well as the conversion per pass of propane and CO2 is 17.74% and 5.08%, respectively.