Author/Authors :
Lu, CL Nanjing University, China , JG, LV Nanjing University, China , Xu, L Nanjing University, China , Guo, X F Nanjing University, China , Hou, W H. Nanjing University, China , Hu, Y. Nanjing University, China , Huang, H. Nanjing University, China
Abstract :
Crystalline nanotubes of gamma-AIOOH and gamma-Al2O3 have been synthesized. An anionic surfactant-assisted hydrothermal process yields gamma-AIOOH nanotubes, and appropriate calcination treatment of the gamma-AIOOH nanotubes yields y-Al2O3 nanotubes. The nanotubeswere characterized by XRD, SEM, TEM, TG-DSC, FTIR and nitrogen adsorption-desorption techniques. Both the gamma-AIOOH and gamma-Al2O3 nanotubes are crystalline, with a representative length of ~500 nm and diameters of 20-40 nm. The gamma-Al2O3 nanotubes exhibit a very high mesoporous specific surface area (SSA) of 201.0 m^2 g^-1 and a high mesopore volume of 0.68 cm^3 g^-1 with an average mesopore size of 27.7 nm, as well as a high microporous SSA of 186.0 m^2 g^-1 and a micropore volume of 0.08 cm^3 g^-1 with an average micropore size of0.53 nm. The formation process was discussed and a possible mechanism was proposed, in which a lamellar phase was first formed by camphorsulfonic anions and AI(III) species, and then rolled up to form the crystalline nanotubes under the hydrothermal condition. The catalyticperformance of the obtained gamma -Al2O3 nanotubes was tested by using the dehydration of ethanol to ethylene as a probe reaction and it was shown that the obtained gamma-Al2O3 nanotubes catalyst possesses a higher catalytic activity compared with the gamma-Al2O3 nanoparticles
