HREELS study of Au/Fe2O3 thick film gas sensors

CO gas sensors based on Au-doped/Fe2O3 thick films were studied in ultra-high-vacuum (UHV) by high resolution electron energy loss spectroscopy (HREELS). Several adsorbed species were identified on HREEL spectra collected at room temperature on thick films annealed at different temperatures. Among these, carboxylate and formate species were postulated as intermediates of the complex reactions occurring on the surface between carbon monoxide and oxygen. talytic and sensing properties of the Au/iron oxide samples towards CO have been also investigated showing the better performances of the co-precipitated samples in comparison to impregnated ones and the influence of annealing temperature. Data reported were correlated to the presence of oxygenate intermediates detected by HREELS.