Vanadium oxide supported on mesoporous SBA-15 as highly selective catalysts in the oxidative dehydrogenation of propane

Dehydrogenation of Isobutane with Carbon Dioxide over SBA-15-Supported Vanadium Oxide Catalysts

“…This is consistent with the reported results [24,25]. A decrease in the intensity of the main (100) peak with an increase in vanadium content is observed, which may be caused by a partial degradation of the hexagonal arrangement of SBA-15 pores [26]. Nevertheless, three clear diffraction peaks still occurred for the SBA-15-supported samples at a V content of up to 7%, implying that the SBA-15 framework is well retained upon supporting vanadia.…”

“…The number of acid sites present on 7% V/SBA is 0.112 mmol/g, which is lower than that on 7% V/MCM (0.143 mmol/g). On the other hand, in consideration of a total V 5+ -to-V 3+ reduction for every H2 molecule consumed, the calculated average oxidation state (AOS) of vanadium after H2 reduction [26] was listed in Table 1. The reduction of vanadium species happens from initial V 5+ to V 4+ and/or V 3+ [30], but the final vanadium oxidation states depend on the V content.…”

Anomalous reactivity of supported V2O5 nanoparticles for propane oxidative dehydrogenation: influence of the vanadium oxide precursor

“…Some researchers have reported a significant increase in the catalytic turnover frequency (TOF: reaction rate per VO x site) with increasing vanadia loading on the support 8,[16][17][18]20,22,24 while other researchers have found a relatively constant TOF with increasing vanadia loading on the supports. 19,21,23,[25][26][27][28][29][30][31][32] A close examination of the propane ODH catalysis literature reveals several different catalyst synthesis methods have been used by the researchers in this field and it is important to better understand the influence of the different preparation methods on the different supported VO x structures and their specific TOF values. To address the influence of the synthesis method upon the molecular structure and specific activity of the different supported VO x phases for propane ODH, a series of supported V/SiO 2 , V/TiO 2 , and V/Al 2 O 3 catalysts were prepared by three different methods and precursors (2- …”

Comparative Study of the Physicochemical Properties and Photocatalytic Activity of Modified McM-41 Synthesized by Direct (One-Step) Incorporation and Impregnation

“…[6][7][8][9][10][11][12][13][14][15][16][17] Two methods are usually employed to modify mesoporous molecular sieves with transition metals: direct incorporation (in one step) (DI) 18-22 and wet impregnation (WI). [23][24][25][26][27] The introduction of metal ions into the framework is often favored by the DI of the metal source in the synthesis gel. Meanwhile, WI generally allows reaching a larger amount of metallic species (metallic oxides) loaded on the surface.…”