The behaviors of V2O5-WO3/TiO2 loaded on ceramic surfaces for NH3-SCR

The catalysts of V2O5-WO3/TiO2 loaded on ceramic surfaces were investigated to evaluate the behaviors of catalytic activities, sulfur tolerance, K resistance, activities regeneration for K-poisoned catalyst and Si-modification in consideration the catalysts characterization. The results indicated that the high SCR activities of these catalysts correlated with the large acid amount, the absorbed oxygen and the well-dispersion of vanadium and tungsten on the surfaces. Washing the K-poisoned catalysts with sulfuric acid could partially recover the catalytic activity because of the K dissolution. Moreover, the incorporation of SiO2 with TiO2 considerably improved the resistance toward potassium because of increasing the acidity of the V2O5-WO3/TiO2 catalyst. The NO conversion increased from 26 to 68% for K-poisoned VW/TiO2(C-400) catalyst to 76-98% for K-VW/TiO2-SiO2(9)(C-400) catalyst at 260-410 degrees C. The NH3 absorption of VW/TiO2-SiO2(6)(C-400) was 236.3 mu mol/g, which was much higher than that of VW/TiO2(C-400) (73.3 mu mol/g) (approximately 3.2 times higher). (C) 2015 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.