Porous nanocomposites of M/Ce-K-O (M=Co, Ni, Cu) were prepared by the citrate-gel thermal decomposition and selective reduction process, and the effect of transition metal nanoparticles on their microstructure, catalytic performance were studied by XRD, SEM, BET, XPS and TG analysis. The nanocomposites consist of the fluorite-type matrix of CeO2 nanoparticles about 13-20 nm and metallic nanoparticles ~26 nm. These nanocomposites have a nanoporous structure with high specific surface area and their pore sizes, pore structures, surface morphologies are largely affected by the dispersed nano metal species. For M/Ce-K-O (M=Co, Ni, Cu) nanocomposites, all the catalysts show a high catalytic activity for soot combustion, and among them, the Cu/Ce-K-O nanocomposite has a lowest T50 of 315 °C mainly due to a higher lattice oxygen content and a weaker Cu-O interaction intensity.
Uniform α-alumina microspheres with mean partice size about 5-6 μm were prepared by the catalytic precipitation and calcination process. The spherical hydrated alumina precursor was first synthesized by the precipitation using ammonium aluminum sulfate and urea. During the reaction process, the urea can be decomposed to the mediator urease, which acts as the catalyst to influence the precipitate formation. The as-prepared α-alumina microspheres exhibit a very good shaping ability and the green body shaped by the dry-press process has a low linear shrinkage rate 5.8% at the sintering process.
Thermal conducting silicone rubber composites filled with aligned nickel (Ni) nanoparticles induced by magnetic field were prepared by the solution mixing process. The structure, thermal, dielectric and magnetic properties of the silicone rubber composites were investigated by optical microscopy, laser flash thermal diffusivity analyzer, LCR digital meter and vibrating sample magnetometer. The results show that with the induction of magnetic field, Ni nanoparticles aligned form thermal conducting networks resulting in increase of the thermal diffusivity and relative dielectric constant of the silicone rubber composites.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.