Acoustic cavitation—an efficient energetic tool to synthesize nanosized CuO–ZrO2catalysts with a mesoporous distribution

Abstract

A CuO–ZrO₂ catalyst of nanometer size was prepared using a simple precipitation technique, assisted by cavitation, and induced by an environmentally friendly ultrasonic technique. BET surface areas of 349.2 m² g⁻¹ for the as-prepared catalyst and 72.4 m² g⁻¹ for the catalyst calcined in air at 500 °C were obtained when the precursors were subjected to 70% ultrasonic intensity for 4 h. On the other hand, by following a conventional precipitation method using similar precursors, a surface area of 72 m² g⁻¹ was obtained when the precursors were heated to only 80 °C for 20 h. More importantly, only the application of ultrasound lead to the formation of a mesoporous structure. To confirm the ultrasonic cavitational effect in this process, the affect of the ultrasonic intensity in increasing the surface area, as well as in generating the mesopores, was also investigated. Furthermore, from studies of the catalytic activity for decomposing N₂O, it has been observed that the catalyst obtained with 70% ultrasonic intensity clearly exhibits an increased activity compared to the catalyst prepared using 20% ultrasonic intensity. These results clearly indicate that ultrasound-induced cavitation is a new and rapid method for the preparation of supported catalysts. The products were characterized by nitrogen adsorption–desorption isotherms, TGA, XRD, TEM, EDAX, XPS and XRF measurements.