Acoustic excitation applied to thin noble metal films on single crystals enhances the catalytic reactions occurring over these surfaces (1).

Now work in Japan has described the different kinetic behaviours on the two faces of a single LiNbO₃ crystal covered with a thin Pd film during ethanol oxidation using resonant acoustic oscillations (RO) (2). RO causes an anomalous increase in catalytic activity. Activation energy falls from 156 to 36 kJ mol^-1 on the positively polarised, (+)Pd, surface, and to zero on the negatively polarised Pd surface. Oxygen is strongly adsorbed on the (+)Pd surface.