Seeds were utilized to synthesize high crystallinity and an economical SSZ-13 substrate zeolite with relatively high Si/Al ratio (similar to 11) via a solvent-free method. NH3-SCR tests, hydrothermal stability, and many characterizations such as XRD, Al-27-NMR, EPR, H-2-TPR, and XAFS were conducted over the fresh and hydrothermally aged Cu2+ ion-exchanged zeolite catalysts (Cu-SSZ-13). The fresh catalysts showed high deNOx activity and tolerance to high space velocity in the temperature range from 150 to 550 degrees C. The active Cu2+ ions were hydrothermally stable, resulting in only slight decrease after hydrothermal aging at 800 degrees C for 16 h. The results showed that the Cu ion-exchanged SSZ-13 catalyst synthesized by the solvent-free method is a promising alternative candidate for actual implementation in diesel engines.