Regeneration of deactivated commercial SCR catalyst by alkali washing

The regeneration of SCR catalyst by dilute sodium hydroxide solution was investigated. For the deactivated catalyst, the porosity disappeared and the specific surface area decreased largely, and there were impurities in deposit and variation of V valences. The dilute sodium hydroxide had a positive influence on the surface of catalysts. The porosity partly recovered and the specific surface area increased 12.75-fold, the impurities also decreased, and the amount of V^{4 +} was partly recovered. After regeneration, the relative activity (k/k₀) at 380 C increased from 0.14 to 0.74. The alkali solution washing might be a promising approach for the regeneration of SCR catalyst.