Effects of Thickness Extension Mode Resonance Oscillation of Acoustic Waves on Catalytic and Surface Properties. III. Ethanol Decomposition on a Thin Ag Film Catalyst Deposited on Negatively Polarized z-cut LiNbO₃

Abstract

The effects of thickness extension mode resonance oscillation (TERO) of bulk acoustic waves on ethanol decomposition over a 100 nm Ag film deposited on a negatively polarized z-cut LiNbO 3 crystal ((-)Ag) were studied, and the results were compared with those obtained previously for Ag deposited on a positively polarized z-cut LiNbO 3 crystal ((+)Ag). In ethylene and acetaldehyde production, the TERO for (-)Ag increased the selective for ethylene production, but the TERO effects on activity and selectivity enhancement were smaller compared to those for (+)Ag. Laser Doppler measurements showed that lattice displacements caused by the TERO were similar between (-)Ag and (+)Ag. In photoelectron emission spectra of (-)Ag, the TERO caused the positive shifts of the threshold energy for electron emission associated with the work function of the Ag surface. The work function increases were considerably smaller for (-)Ag than for (+)Ag, which is considered to be responsible for differences in the catalyst activation between (-)Ag and (+)Ag. A mechanism of different TERO effects between (-)Ag and (+)Ag is discussed.

Controllable CO2 electrocatalytic reduction via ferroelectric switching on single atom anchored In2Se3 monolayer

“…Inspired by these recent achivements, we expect that ferroelectrics, viz ., materials with switchable ferroelectric polarization, hold promise as efficient catalysts since their unique reversible polarization provides an additional mechanism to adjust empty and occupied d- orbitals of adsorbed metal atoms. The activation of reactants can thus be controlled, while the catalytic properties of the supported metal, such as activity 29 – 32 and selectivity, can be tuned 33 . These expectations have been partially confirmed in ABO 3 perovskite ferroelectrics.…”

Ferroelectric surface chemistry: First-principles study of the PbTiO3surface

“…In addition, several experimental works on ferroelectric-supported metals, including BaTiO 3 -supported Ni and LiNbO 3 -supported Cu and Au, observed changes in catalytic activity correlated with the ferroelectric-paraelectric transition. [12][13][14][15] In this work, we use first-principles density functional theory to investigate the effects of polarization on the (001) surface of PbTiO 3 . We investigate the consequences of changing polarization on stoichiometric surfaces and determine the thermodynamically stable (nonstoichiometric) surface structures as a function of the film polarization.…”

Polarization Effects on the Surface Chemistry ofPbTiO3-Supported Pt Films

“…Another study found increased activity towards ethanol oxidation on Cu and Au surfaces supported by ferroelectric LiNbO 3 and attributed this activation to the presence of the electric field at the polarized LiNbO 3 surface [14]. In other work, ferroelectric supports have been used to generate acoustic waves, which have been shown to both activate and increase the selectivity of Ag, Pd, and Ni catalysts for alcohol oxidation and decomposition [15].…”