Effects of resonance oscillation with a thickness-extensional mode on activation of thin film metal and metal oxide catalysts deposited on poled ferroelectric substrates

The effects of resonance oscillation RO. with a thickness-extensional mode generated in a poled ferroelectric z-cut LiNbO3 single crystal by rf power were studied on reaction selectivity for the ethanol decomposition of thin film Au, Ag and WO3 catalysts deposited. For a 100 nm Ag catalyst, a 3.5 MHz RO at 3 W caused an increase in ethylene production at 573 K by a factor of 16 without any change in acetaldehyde production. The selective promotion of ethylene production by RO was also observed at 573 K for a Au catalyst in which the activity for ethylene production increased by a factor of 5. For a WO3 catalyst the RO increased both the ethylene and acetaldehyde productions, but the former was more largely promoted than the latter. The RO caused decreases in respective activation energy. The selective production of ethylene is associated with the RO-induced strong oxygen–metal and metal oxide.surface interactions which are produced by dynamic lattice displacement. q1999 Elsevier Science B.V. All rights reserved.