Enhancement of nitric oxide reduction via CeZrOx/Cu‐SSZ‐39 hybrid catalyst: Improving activity and hydrothermal stability

Abstract This study aimed to improve the catalytic activity and hydrothermal stability of Cu‐SSZ‐39 zeolite by coupling it with cerium zirconium oxides (CeZrO x ), which possesses excellent oxidizing ability, and a hybrid catalyst CeZrO x /Cu‐SSZ‐39 was prepared. It is found that it exhibited enhanced low‐temperature activity, high‐temperature activity, and a wider effective temperature range compared to Cu‐SSZ‐39. Characterization results showed that the CeZrO x /Cu‐SSZ‐39 catalyst had a higher concentration of active Cu 2+ ion species and improved redox properties, which could potentially promote the NH 3 ‐SCR reaction. Additionally, the CeZrO x /Cu‐SSZ‐39 catalyst had increased chemisorbed oxygen species on its surface, facilitating the oxidation of NO to NO 2 and enhancing the rate of the SCR reaction. Moreover, even after undergoing hydrothermal aging treatment, the CeZrO x /Cu‐SSZ‐39 catalyst exhibited superior catalytic activity and improved hydrothermal stability, surpassing the performance of Cu‐SSZ‐39. It is found the CeZrO x coupling allowed the hybrid catalyst to maintain a better specific surface area and pore structure during hydrothermal aging, resulting in reduced activity loss. Therefore, the addition of CeZrO x enhanced the NH 3 ‐SCR activity of Cu‐SSZ‐39 zeolite, leading to improved catalytic activity and hydrothermal stability. CeZrO x /Cu‐SSZ‐39 catalyst has shown promising aspect for reducing NOx emissions from diesel vehicle exhaust.