Developmert of Scanning Chemical Potertial Microscope

点击翻译按钮获取中文摘要

The objective of this research has been to develop a "scanning chemical potential microscope" that measures the chemical potential profiles on catalysts or electrodes in order to investigate the reaction kinetics. In this research project, we have invented an oxygen potential probe, and applied it for the investigation of gas electrode reaction on a solid oxide electrolyte.(1)The concept of Porous Oxygen Sensor (POS), was developed. Stabilized zirconia or ceria was sintered into a porous pellet, and put on a sample surface. Oxygen potential on the sample surface was measured against a Pt reference electrode that was applied on the other side of POS by a potentiometric method.(2) The POS method was successfully applied to the kinetic study of oxygen incorporation reaction through a mixed ionic / electronic conductor electrode. The overvoltage for the two surface reaction processes were determined by using POS.(3) Kinetic model and the parameters obtained by POS were quite reasonable, proving that POS method is usable for a quantitative analysis.(4) POS microprobes were fabricated by coating zirconia powders on Pt based metal wires. The topologically identical structure with normal POS was realized in a micrometer space. A commercial probe for micro thermal analysis was used as a fine Pt-Rh probe base. It was coated with YSZ in two methods, i.e. slurry coating and thermal decomposition of metal organic precursors. By the latter method, a fine probe with lateral resolution higher than one micron was fabricated.(5) Sample heating stage was fabricated for the in-situ measurements of YSZ based electrolyte. It was installed on an atomic force micro probe scanner, and operated at 700 ℃.(6) Space resolved analysis of surface oxygen potential was successfully performed on a LaMnO3 based electrode.