Strategy on Effective Synthesis of SSZ-13 Zeolite Aiming at Outstanding Performances for NH3-SCR Process

SSZ-13 zeolite was synthesized using four templates, and the synthesis conditions with choline chloride (CC) as template were optimized by dynamic stirring, fluoride-assisted and seed-assisted synthesis. Because the geometric dimensions of CC dimer (7.21 × 10.72 A) and CHA cage (7.3 × 12 A) matched closely, the crystallinity and specific surface area of sample synthesized using CC were higher than those of other samples (except for that of the sample synthesized using TMAdaOH). By adopting three improved methods, SSZ-13 samples with better crystallinity, higher specific surface area and more regular morphology could be synthesized in a shorter time (3–4 days). The sample prepared using fluoride-assisted method could achieve a similar crystallinity to the sample synthesized using TMAdaOH. The corresponding catalyst exhibited the best catalytic performance in the NH3-SCR reaction, with 100% NO conversion from 150 to 550 °C. This performance was attributed to fluoride ions promoting the formation of CC dimers through charge attraction of SiF62−. Furthermore, by synthesis optimization, the more developed pore structure, stronger NH3 adsorption capacity and lower CuO content of Cu-SSZ-13 were also important factors for the improved catalytic performance.