Abstract: Ag-hollandite nanofibers were synthesized by refluxing a mixture of AgMnO4 and Mn(NO3)2 in nitrate acid solution at 373 K and used for ethanol selective oxidation. TheX-raydiffraction pattern showed that the main crystalline phase was Ag-hollandite, but a small amount of pyrolusite was also formed. The N2 adsorption-desorption isotherms confirmed the presence of a microporous structure. Field emission scanning electron microscopy and transmission electron microscopy showed that the lengths of the nanofibers were0.5-4.0μm, and the diameters were 10-20 nm. The Ag-hollandite nanofibers gave a promising catalytic performance for ethanol selective oxidation to acetaldehyde, with an ethanol conversion of 82% and acetaldehyde selectivity of 95% at 503 K for 120 h time-on-stream.

Key words: silver, hollandite, nanofiber, ethanol oxidation