Influence of Self-organization of Al2O3 and TiO2/Al2O3 Nanofilaments into Nanotubes Caused by High Temperature Hydrogen Treatment on Propane Cracking

Title:Influence of Self-organization of Al2O3 and TiO2/Al2O3 Nanofilaments into Nanotubes Caused by High Temperature Hydrogen Treatment on Propane Cracking

Volume: 8 Issue: 1

Author(s): Olga K. Krasilnikova*, Ekaterina B. Markova, Tatiana Y. Grankina, Elena V. Khozina and Valery N. Simonov

Affiliation:

• Frumkin Institute of Physical Chemistry and Electrochemistry of RAS, Moscow,Russian Federation

Keywords: Alumina nanotubes, TiO2/Al203 nanotubes, self-organization of alumina nanofilaments, cracking of propane, ethylene, propylene.

Abstract: Introduction: New nanomaterials based on porous amorphous aerogels composed of Al2O3 nanofilaments with a diameter of 5 nm were obtained by oxidation of metallic aluminum. Al2O3 nanofilaments were covered by a TiO2 monolayer to prepare a TiO2/Al2O3 composite aerogel. It has been shown that the hydrogen treatment of inactive aerogel formed by alumina nanofilaments and its composite TiO2/Al2O3 at temperatures of 923-1173 K gave rise to a catalytic activity in the cracking of propane. It was found that the hydrogen treatment at high temperatures resulted in the self-organization of Al2O3 intertwined nanofilaments (5 nm in diameter) and TiO2/Al2O3 composite into the η-Al2O3 nanocrystalline hollow nanotubes with a diameter of 33 nm and 6 nm-thick walls followed by packing these nanotubes into bundles. This transformation was evidenced by electron microscopy, transmission electron microscopy, low-temperature adsorption of nitrogen vapors, X-ray fluorescence and X-ray diffraction.

Method: The high-temperature hydrogen activation of aerogels prepared from Al2O3 and Al2O3/TiO2 nanofilaments significantly added to their efficiency in the cracking of propane compared both to the commercial platinum catalyst supported by alumina and the thermal cracking, as well.

Result & Conclusion: The mesoporous crystalline structure of alumina nanotubes ensured a high selectivity (63% ethylene) and a catalytic activity (0.3 mmol/g×s) in the cracking of propane over the temperature range of 923-1123 K. In the case of TiO2/Al2O3 nanotubes, the reaction products changed from ethylene mainly to propylene with the selectivity of 68% and the catalytic activity of 0.1 mmol/g×s in the same temperature range.

Cite this article as:

Krasilnikova K. Olga*, Markova B. Ekaterina, Grankina Y. Tatiana, Khozina V. Elena and Simonov N. Valery, Influence of Self-organization of Al2O3 and TiO2/Al2O3 Nanofilaments into Nanotubes Caused by High Temperature Hydrogen Treatment on Propane Cracking, Nanoscience & Nanotechnology-Asia 2018; 8 (1) . https://dx.doi.org/10.2174/2210681206666160909115904