The Mo Loading Effect on Thermo Stability and SO2 Oxidation of SCR Catalyst

Abstract

The SCR catalysts were produced with V2O5, WO3, MoO3 and anatase type TiO2. The thermo stability of the catalyst with different MoO3 loading was analyzed with TG-DTG. And the SO2 oxidations were researched with a fixed bed reactor under simulated exhaust gas. The different loadings of MoO3 did not effect on the thermo stability of the catalyst with temperature in the test range of 30~1000 °C. The TG–DTG curves of thermal decomposition process of V2O5-WO3-MoO3/TiO2 catalyst showed three mass loss segments: 1st the evaporation of crystal water from 70 °C to 130 °C; 2nd the decomposition of organics from 180 °C to 350 °C; 3rd the decomposition of impurities from 480 °C to 550 °C. The catalyst loading MoO3 showed higher catalytic selectivity compared to the catalysts without MoO3. MoO3 contained in the catalysts prevented SO2 oxidation, improving the oxidation start temperature and reducing the maximum oxidation.