Direct synthesis of high silica SSZ-16 zeolite with extraordinarily superior performance in NH3-SCR reaction

Abstract

The development of Cu ion-exchanged small-pore zeolites with excellent performance and high hydrothermal stability in NH3-SCR reaction is of great importance. However, many frameworks of the small-pore zeolites are Al-rich, for instance, Cu-SSZ-16 zeolite with Si/Al ratio always no more than 5, showing relatively low hydrothermal stability. In this work, inspired by theoretical calculation for the interaction between organic structural directing agents (OSDAs) and zeolite framework, high silica SSZ-16 zeolite with Si/Al ratio at 6.7 was directly synthesized using an economical diquaternary alkylammonium cation as an OSDA. After exchanged with Cu ion, the Cu-SSZ-16 catalyst shows extraordinarily superior performance in NH3-SCR reaction even after hydrothermal aging at 900 °C. The designed synthesis combined with excellent performance as well as high hydrothermal stability of the high silica SSZ-16 zeolite might provide an attractive alternative candidate for NH3-SCR catalyst on diesel vehicles and non-road mobile machinery in the future.