Effect of potassium addition on catalytic activity of SrTiO3 catalyst for diesel soot combustion

▶ The positive effect of potassium addition on the catalytic activity of strontium titanate in soot oxidation can be interpreted in terms of two mechanisms of potassium action: enhancement of oxygen surface mobility and oxygen vacancies formation in the oxygen sublattice of perovskite structure depending on the potassium localization. ▶ The experimental results (potassium volatility, work function changes, basicity, XPS spectroscopy) revealed that the vacancy mechanism is the most efficient in stimulating the soot combustion catalytic reactivity of strontium titanate.