EFFECT OF SURFACE ACOUSTIC-WAVES ON ACTIVITY IN HETEROGENEOUS CATALYSIS

A synopsis of the recent developments in acoustically influencing and controlling gas-surface interactions is presented. The cleaning effect of ultrasound and its surface activation play an important role for t he sonochemical enhancement of reactivity in chemical processes involv ing solid and liquid phases. So far, there have only been a few studie s on the effects of surface acoustic waves on surface chemical reactio ns under high-vacuum conditions by the application of piezoelectric su rface acoustic wave transducers. Very recently, metal films deposited between InterDigital Transducer (IDT) electrodes on a LiNbO3 substrate have shown a significant increase in catalytic activity during surfac e acoustic excitation and Edge-Bonded Transducers (EBT) with a metal s ingle crystal as a substrate have been used to acoustically influence the rate in the oscillatory reaction for CO oxidation. Tunable narrowb and surface acoustic excitation is anticipated to be an efficient rout e to control catalytic processes, and in our work this approach is bei ng used to investigate the physical basis of this process.