Effect of Microgravity on Synthesis of Nano Ceria

Catalysts

Ilgaz I. Soykal²  Hyuntae Sohn²  Burcu Bayram²  Preshit Gawade²  Michael P. Snyder¹  Stephen E. Levine¹  Hayrani Oz¹  Umit S. Ozkan² 

[1] Mechanical and Aerospace Engineering, the Ohio State University, 201 W. 19th Street, N350 Scott Laboratory, Columbus, OH 43210, USA; E-Mails:;William G. Lowrie Department of Chemical and Biomolecular Engineering, the Ohio State University, 151 W. Woodruff Avenue, Columbus, OH 43210, USA; E-Mails:

关键词: microgravity;    gravity;    cerium oxide;    ceria;    synthesis of ceria;    morphology;    particle size;    nanorods;   

DOI  :  10.3390/catal5031306

来源: mdpi

【 摘 要 】

Cerium oxide (CeO₂) was prepared using a controlled-precipitation method under microgravity at the International Space Station (ISS). For comparison, ceria was also synthesized under normal-gravity conditions (referred as control). The Brunauer-Emmett-Teller (BET) surface area, pore volume and pore size analysis results indicated that the ceria particles grown in space had lower surface area and pore volume compared to the control samples. Furthermore, the space samples had a broader pore size distribution ranging from 30–600 Å, whereas the control samples consisted of pore sizes from 30–50 Å range. Structural information of the ceria particles were obtained using TEM and XRD. Based on the TEM images, it was confirmed that the space samples were predominantly nano-rods, on the other hand, only nano-polyhedra particles were seen in the control ceria samples. The average particle size was larger for ceria samples synthesized in space. XRD results showed higher crystallinity as well as larger mean crystal size for the space samples. The effect of sodium hydroxide concentration on synthesis of ceria was also examined using 1 M and 3 M solutions. It was found that the control samples, prepared in 1 M and 3 M sodium hydroxide solutions, did not show a significant difference between the two. However, when the ceria samples were prepared in a more basic medium (3 M) under microgravity, a decrease in the particle size of the nano-rods and appearances of nano-polyhedra and spheres were observed.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.