Effect of preparation conditions of V2O5/TiO2 catalysts for selective catalytic reduction of NOx with NH3

Abstract

International Maritime Organization (IMO) announced Tier Ⅲ taking effect from 2016 which regulates NOx emitted from vessels. Marine SCR catalyst requires higher DeNOx activity in the low temperature range comparing to automobile. In this study, I aimed at finding the optimum condition to prepare V2O5/TiO2 catalyst known as low temperature selective catalytic reduction catalysts by changing oxidation states in vanadium precursor solution. V2O5 catalysts supported by TiO2 (1, 3, 5 and 7 wt%) were prepared by applying wet impregnation method using three precursor solutions with different oxidation states (V3+, V4+ and V5+). I utilized BET, ICP, XRD, Raman spectroscopy, UV-Vis DRS, H2 TPR and XPS to investigate the physicochemical properties of V2O5/TiO2 catalysts. Also, NH3-SCR reaction test was performed for these catalysts. It was found that V2O5/TiO2 catalysts prepared from the precursor solution of V3+ oxidation state (VT(3+)) has good activity over wide temperature range and produces the lowest concentration of N2O during SCR reaction. The formation of highly coordinated polymeric vanadyl species on the sample attributes the high NOx conversion and low production of N2O of the VT(3+) catalyst.