Heterogeneous catalysts often require rare and expensive metals. The use of ultrasound offers some hope of activating less reactive, but also less costly, metals. Scanning electron micrograph of 5 m m diameter Zn powder. Neck formation from localized melting is caused by high-velocity interparticle collisions. The effect of ultrasonic irradiation on the surface morphology and particle size of Ni powder.
Upper image is before ultrasound and lower is after irradiation of a slurry in decane.
High-velocity interparticle collisions caused by ultrasonic irradiation of slurries are responsible for the smoothing and removal of passivating oxide coating. Highlighted articles are downloadable in PDF format. To get the free Adobe PDF reader, click on this text.