Component synergistic catalysis of Ce-Sn-W-Ba-Ox/TiO2 in selective catalytic reduction of NO with ammonia

Abstract The component synergistic catalysis of the Ce-Sn-W-Ba-Ox/TiO2 in selective catalytic reduction of NO (in the presence/absence of H2O and SO2) was investigated. Results verified that CeO2 was an essential primary active component, and WO3, SnO2 and BaO were essential cocatalyst. TiO2 provided enough acid sites, CeO2 enhanced redox properties, weakened acid strength and increased chemisorbed oxygen concentration, which was beneficial to accelerate the activation and desorption of NH3. SnO2 increased chemisorbed oxygen concentration, enhanced redox properties and improved activation rate of NH3. WO3 increased acid amount and BaO enhanced the anti-influences to water vapor and SO2. Their synergistic effects made Ce-Sn-W-Ba-Ox/TiO2 exhibit excellent catalytic performance for NH3-SCR, reaching the highest value about 100% at 350 °C in presence of H2O and SO2. Moreover, in situ DRIFTS study showed that the reaction followed L-H mechanism at high temperature and tended to simultaneously follow E-R and L-H mechanisms at low temperature.