Synthesis of Nanocomposites Based on NiCu/LaNb0,8Mo0,2O4 for Proton-Conducting Membranes
Доклады на конференциях
In the last decade proton transport has been intensively studied in materials with appreciable mixed electronic-proton conduction for development of hydrogen transport membranes and fuel cells. The purpose of this study is to create a coarsely dispersed layer for a multilayer dense cermet proton-conducting membrane. This type of membrane is characterized by high thermomechanical and chemical stability, selectivity, and a high diffusion rate. The mixture for nanocomposites includes NiCu and orthoniobates to improve electronic conductivity and to increase a conducting capacity and stability in H2O- and CO2-containing atmospheres. Besides, doping LaNbO4 with a number of metals (Ca, Mo and etc.) allow to improve ionic conductivity.
The samples of orthoniobates LaNb0,8Mo0,2O4 and composite LaNb0,8Mo0,2O4/NiCu (65:35 wt.%) were prepared using simple, fast and ecological method - mechanochemical activation in a planetary mill. Studies of orthoniobates structural properties genesis by using thermal analysis, XRD, IR and Raman spectroscopy have revealed that MA results in formation of LaNb0,8Mo0,2O4 with fergusonite structure already after 15 min milling. For comparing an ultrasonic dispersion method was also used for obtaining nanocomposite. The results showed that mechanical activation makes it possible to obtain a single-phase nanocomposite with more average particle size. High-density ceramic and nanocomposite pellets have been obtained after sintering at 1100-1300 °C. For all samples the electrical conductivity values measured in a humid atmosphere (up to ~ 10-3 S/cm at 550 °C) exceed those measured in a dry atmosphere indicating the proton character of conductivity.