Accelerated synthesis of deca-dodecasil 3 rhombohedral (DDR3) zeolite crystals via hydrothermal growth coupled with ultrasonic irradiation method

Abstract

In the present work, DDR3 zeolite crystals were synthesized via hydrothermal heating coupled with ultrasonic irradiation method. The duration of hydrothermal heating was varied from 0.5–10 days and the temperature was maintained at 160 °C. Meanwhile, the duration of ultrasonic irradiation was varied from 1 h to 3 h. The crystallinity, surface morphology and bond vibration of the resultant samples were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The XRD results showed that the peaks representing DDR3 structure were obtained for the sample synthesized in 10 days with ultrasonic irradiation of 3 h. XRD peaks of the sample synthesized in 5 days with ultrasonic irradiation of 2 h also demonstrated the structure of DDR3 topology. Samples synthesized in 1, 2 and 5 days with ultrasonic irradiation of 1 h also demonstrated the structure of DDR3 topology. However, the sample synthesized in 0.5 day with 1 h of ultrasonic irradiation didn't showed DDR3 topology due to absence of major peaks in XRD pattern. For comparison purpose, reference DDR3 crystals were synthesized in 25 days without ultrasonic irradiation. From these results, it can be concluded that conventional hydrothermal heating coupled with ultrasonic irradiation has successfully reduced the synthesis duration of DDR3 zeolite from 25 days to 1 day.