Impact of Surface Roughness on Recrystallization of an α-AlO(001) Single Crystal to α-AlO(OH) Diaspore Microcrystals.

We demonstrate that the surface of an α-AlO(001) single crystal recrystallizes to α-AlO(OH) under ultrahigh pressure (8 GPa) at 600 °C. The recrystallization depends on the degree of surface roughness. A polished surface topotaxially recrystallizes to (100)-oriented α-AlO(OH) microcrystals, while unpolished surface recrystallizes to polycrystalline α-AlO(OH).

Probing the temperature of supported platinum nanoparticles under microwave irradiation by in situ and operando XAFS.

Microwave irradiation can cause high local temperatures at supported metal nanoparticles, which can enhance reaction rates. Here we discuss the temperature of platinum nanoparticles on γ-AlO and SiO supports under microwave irradiation using the Debye-Waller factor obtained from in situ extended X-ray absorption fine structure (EXAFS) measurements. Microwave irradiation exhibits considerably smaller Deby-Waller factors than conventional heating, indicating the high local temperature at the nanoparticles.

Remote Control of Electron Transfer Reaction by Microwave Irradiation: Kinetic Demonstration of Reduction of Bipyridine Derivatives on Surface of Nickel Particle.

Microwave irradiation has great potential to control chemical reactions remotely, particularly reactions that involve electron transfer. In this study, we found that the reduction reaction of bipyridine derivatives on metal nickel particles was accelerated or decelerated by 2.45 GHz microwaves without an alteration of the reaction temperature.

Enhancement of anodic current attributed to oxygen evolution on α-FeO electrode by microwave oscillating electric field.

Various microwave effects on chemical reactions have been observed, reported and compared to those carried out under conventional heating. These effects are classified into thermal effects, which arise from the temperature rise caused by microwaves, and non-thermal effects, which are attributed to interactions between substances and the oscillating electromagnetic fields of microwaves. However, there have been no direct or intrinsic demonstrations of the non-thermal effects based on physical insights.