Role of surface vanadium oxide coverage support on titania for the simultaneous removal of o-dichlorobenzene and NOx from waste incinerator flue gas

The catalytic activity of VOx species supported on TiO2 was investigated in the simultaneous destruction of NO and 1,2-dichlorobenzene (o-DCB), as typical pollutants molecules in the off-gases from municipal waste incinerator (MWI) plants. Catalysts with different vanadium loading were prepared in order to obtain different VOx species and characterized by ICP-AES, XPS, N2 adsorption at −196 °C, XRD, H2-TPR, Raman and UV–vis–NIR DRS spectroscopy. The characterization results show that molecularly dispersed isolated and polymeric vanadia species form below the dispersion limit loading (“monolayer coverage”), while crystalline species form above it. We used moderate HNO3 treatment to partially leach vanadium oxide species, creating a series of catalysts with variable vanadia loading. The catalytic activity of the VOx/TiO2 catalyst shows that it is able to catalyze the destruction of both pollutants, although higher temperature is required for o-DCB oxidation than for NO reduction. Surface vanadia coverage has a clear effect on TOF and activation energy values, which underline that isolated vanadia species are more efficient for o-DCB oxidation, while the polymeric ones are more efficient for NO reduction.This research was funded by Basque Government though the Grant to Consolidated Research Groups (GIC-07/67-JT-450-07) and the SAIOTEK program (S-PE11UN074), by University of the Basque Country UPV/EHU through the UFI (UFI 11/39) and the Grant for the acquisition and renovation of scientific infrastructure (INF12/37) and by the Spanish Ministry of Economy and Competitiveness (CTM2012-31576). One of the authors (MGV) acknowledges also the Basque Government for the PhD Research Grant (BFI-2011-238).Peer Reviewe

Oxidation of volatile organic compounds by highly efficient metal zeolite catalysts

The presence of two metals (M1M2) in a zeolite structure enhances the degradation of pollutants in liquid or gas phase comparing to monometallic catalysts. In this work, the complete oxidation of ethyl acetate into CO2 was achieved by metal catalysts based on NaY zeolite prepared by the ion-exchange method. The metal zeolite catalysts were optimized by used several parameters: (i) the presence of a second metal in M1M2 catalysts; (ii) the presence or not of a noble metal in the pair CuM2 (M2=Pd, Zn or Ag); (iii) the order of introduction of the metals in M1M2 catalysts (CuPd or PdCu); (iv) particle size of NaY and NaYnano; and (v) the effect of simultaneously adding metal species (Cu and Pd). M1M2 catalysts presented the best results compared to the monometallic catalysts and the presence of a noble metal in M1M2 catalysts enhanced their acivity. Among the metal phases studied, the catalyst (CuPd)0.01-Y was shown to be the most efficient for this application.This work has been developed under the scope of the projects: BioTecNorte (operation NORTE-01-0145-FEDER-000004) and “AIProcMat@N2020-Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, NORTE-01-0145FEDER-000006, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by national funds (FCT, Fundação para a Ciência e a Tecnologia), through the projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID/QUI/ 00686/2013 and UID/QUI/0686/2016) and LSRE/LCM (POCI-010145-FEDER-006984).info:eu-repo/semantics/publishedVersio