Ytterbia (Yb2O3) is an oxide ceramic, whose magnetic properties and crystal structure were studied to some extent in the past. However, the information on Yb2O3's catalytic properties is lacking. Therefore, in this work, the sintering behavior and catalytic properties of Yb2O3 were examined. Yb2O3 ceramic samples were made using pressureless sintering of the commercially available Yb2O3 with 99.99% purity powder. The powder was first uniaxially pressed at 20 MPa in a steel die followed by pressureless sintering at different temperatures of 900 ⁰C to 1600 ⁰C for 4 hours. The densities of these samples were measured, and the sample sintered at 1600 ⁰C had the largest density of 62.88% and 900 ⁰C samples had the lowest of 45%. To improve the density of samples, three samples were uniaxially pressed same as the previous samples; however, they were also cold isostatically pressed at 260 MPa. These samples yielded the highest density of 90% after sintering at 1700 ⁰C for 4 hours. Raman spectra of sintered Yb2O3 were collected, which corresponded very well to those published in the literature. The microstructure of sintered Yb2O3 was studied by scanning electron microscopy. X-ray diffraction (XRD) showed that Yb2O3 crystallize in an Ia cubic structure. X-ray fluorescence (XRF) was performed and it confirmed high counts of Yb and high purity of Yb2O3 powder. The catalytic experiments were performed on highly porous Yb2O3 samples sintered at 900 ⁰C. In the first experiment, Syn gas (H2 + CO) was passed over Yb2O3 at 30 psig at 400 ⁰C with a rate of 3 cc/m. In the second experiment, the temperature was lowered to 250 ⁰C with all other conditions of the experiment maintained the same. As a result of the first reaction, the products included methane, ethane, and ethylene. The products produced in the second trial were ethane, ethylene, propene, butane, butene, cyclobutene, and methyl alcohol.
Bachelor Science in Aerospace Engineering (B.S.A.E.)
College of Engineering and Computer Science
Mechanical and Aerospace Engineering
Aftab, Alina, "Sintering Behavior, Structural, and Catalytic Properties of Ytterbium Oxide (Yb2O3)" (2019). Honors Undergraduate Theses. 641.