Publikace detail

CO Adsorption on VOx /SBA-15 Catalysts: an FTIR Spectroscopic Study

Autoři: Bulánek Roman | Drenchev Nikola Lyudmilov | Čičmanec Pavel | Setnička Michal

Rok: 2012

Druh publikace: ostatní - přednáška nebo poster

Strana od-do: nestránkováno

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
eng	CO Adsorption on VOx /SBA-15 Catalysts: an FTIR Spectroscopic Study	Carbonyls of vanadium on fully oxidized sample are not observe because of covalent character of the V-O bonds and coordinatively saturation of V+5 cations. Reduction process is noticeable at 4500C. Small amount of V atoms reduce at this temperature for 1 h. Different oxidation states (V+4 and V+3) and two different species of V3+ are established after CO adsorption at 77 K. The main part of reduced V atoms are in +3 oxidation state. Spectra of reduced samples show increasing in intensity of silanol groups, caused by dissociation of V-O(Si) bonds and formation of new H-O(Si) bonds. Reduction occurs with formation of water. The band corresponds to overtone of V=O stretching modes decreases in intensity because of oxygen withdrawing from V=O species. Different oxidation states (V+4 and V+3) and two different species of V4+ and V3+ are established after NO adsorption at ambient temperature. A Part of V3+ cations form mononitrosyls characterize by band at 1724 cm-1.	CO; adsorption; VOx; SBA-15; catalyst; FTIR

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