Study on the Gas Sensitivity of a CeO_2 Based Ceramic Sensing Element: Structure and Characteristic

摘要

The sensitivity of CuO dispersed on fluorite-type oxide, namely CeO_2 was studied in this work. Mixed oxide sample of nanostructured Cu_xCe_(1-x)O_(2-y) of various composition were generated by step chemical precipitation method. Distinct copper species were identified as a function of copper content by X-ray photoelectron spectroscopy, X-ray powder diffraction, the special surface areas, transmission electron microscopy, scanning electron microscopy analysis, and sensing properties to CO. It was found that only small amounts of copper are sufficient to promote the sensitivity of CeO_2 by several orders of magnitude, which excessive amounts of copper (Cu/(Cu+Ce)> 0.12) are detrimental to the sensing properties of nanocompositions. The possible causes for this behavior are also discussed.