Bimodal effect of water on V2O5/TiO2 catalysts with different vanadium species in the simultaneous NO reduction and 1,2-dichlorobenzene oxidation
Autor: | A. Aranzabal, Juan R. González-Velasco, J.A. Martín-Martín, M.P. González-Marcos, M. Gallastegi-Villa |
---|---|
Rok vydání: | 2021 |
Předmět: |
General Chemical Engineering
1 2-Dichlorobenzene Inorganic chemistry Vanadium chemistry.chemical_element 02 engineering and technology water effect 010402 general chemistry 01 natural sciences Redox Industrial and Manufacturing Engineering Catalysis chemistry.chemical_compound symbols.namesake Adsorption X-ray photoelectron spectroscopy 1 2-dichlorobenzene Environmental Chemistry vanadium species Chemistry General Chemistry 021001 nanoscience & nanotechnology 0104 chemical sciences symbols VOX/TiO2 0210 nano-technology Selectivity Raman spectroscopy NH3-SCR deactivation |
Zdroj: | Addi. Archivo Digital para la Docencia y la Investigación instname |
Popis: | VOX/TiO2 catalysts with different vanadium loading were prepared in order to study the influence of vanadium species on the effect of water in the simultaneous NO reduction through NH3-SCR and o-DCB oxidation reactions. The presence of isolated, polymeric and crystalline species and their redox and acid properties were evaluated by N2-Adsorption, XRD, Raman, H2-TPR, XPS and NH3-TPD. Water has a bimodal and reversible effect in both NO reduction and o-DCB oxidation depending on vanadium species and temperature. In SCR, water has a detrimental effect at low temperature due to competitive adsorption with NO and NH3, while at high temperature it promotes an increase of NO conversion associated to the suppression of side-reactions, which increase the selectivity towards N2. In o-DCB oxidation, the effect of water is the sum of two contributions: one positive, related to the removal of surface adsorbed detrimental species; and one negative, associated to the competitive adsorption with o-DCB. Thus, at high temperature water acts as inhibitor, while at low temperature water has a promotional effect in the highly dispersed vanadium catalysts due to their tendency to suffer deactivation, mainly by carbonaceous materials. The presence of water also favors total oxidation and decreases the formation of chlorinated by products. MINECO/FEDER (CTQ2015-64616-P), MINECO/FEDER (BES-2016-077849), IT657-13, IT1297- 19, INF12/37, UFI 11/39, PID2019-107503RB-I00, MCIN/AEI/10.13039/501100011033 |
Databáze: | OpenAIRE |
Externí odkaz: |
načítá se...