Cu-SSZ-39 zeolite with an AEI structure exhibits excellent hydrothermal stability and can be a potential alternative to Cu-SSZ-13 zeolite SCR catalysts for NOx removal in diesel vehicles. Cu-SSZ-39 zeolites have exhibited excellent NH3-SCR catalytic activity and hydrothermal stability, giving them promise for practical application. A high proportion of Cu2+-2Al species and intricate pore structure contribute to its enhanced hydrothermal stability, making it suitable for stringent application conditions[1].