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

• A new type of SCR catalyst loaded on the surface of ceramics using a sol–gel method.
• Washing with sulfuric acid could partially recover the activity of K-poisoned V2O5–WO3/TiO2 catalyst.
• A high activity, excellent SO2 and K resistance was obtained for the Si-modified V2O5–WO3/TiO2 catalyst.
• The addition of Si remarkably improved the acidity of the V2O5–WO3/TiO2 catalyst.

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 °C. The NH3 absorption of VW/TiO2–SiO2(6)(C-400) was 236.3 μmol/g, which was much higher than that of VW/TiO2(C-400) (73.3 μmol/g) (approximately 3.2 times higher).

Si-doped V2O5–WO3/TiO2 catalyst considerably enhanced the acidity of the catalysts, which remarkably increased the resistance toward potassium.Figure optionsDownload as PowerPoint slide