Lu C L, Lv J G, Xu L, Guo X F, Hou W H, Hu Y, Huang H
Key Laboratory of Mesoscopic Chemistry of MOE, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, People's Republic of China.
Nanotechnology. 2009 May 27;20(21):215604. doi: 10.1088/0957-4484/20/21/215604. Epub 2009 May 6.
Crystalline nanotubes of gamma-AlOOH and gamma-Al(2)O(3) have been synthesized. An anionic surfactant-assisted hydrothermal process yields gamma-AlOOH nanotubes, and appropriate calcination treatment of the gamma-AlOOH nanotubes yields gamma-Al(2)O(3) nanotubes. The nanotubes were characterized by XRD, SEM, TEM, TG-DSC, FTIR and nitrogen adsorption-desorption techniques. Both the gamma-AlOOH and gamma-Al(2)O(3) nanotubes are crystalline, with a representative length of approximately 500 nm and diameters of 20-40 nm. The gamma-Al(2)O(3) 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 of 0.53 nm. The formation process was discussed and a possible mechanism was proposed, in which a lamellar phase was first formed by camphorsulfonic anions and Al(III) species, and then rolled up to form the crystalline nanotubes under the hydrothermal condition. The catalytic performance of the obtained gamma- Al(2)O(3) nanotubes was tested by using the dehydration of ethanol to ethylene as a probe reaction and it was shown that the obtained gamma- Al(2)O(3) nanotubes catalyst possesses a higher catalytic activity compared with the gamma- Al(2)O(3) nanoparticles.
已合成出γ-AlOOH和γ-Al₂O₃的晶体纳米管。一种阴离子表面活性剂辅助水热法可生成γ-AlOOH纳米管，对γ-AlOOH纳米管进行适当的煅烧处理可得到γ-Al₂O₃纳米管。通过XRD、SEM、TEM、TG-DSC、FTIR和氮气吸附-脱附技术对纳米管进行了表征。γ-AlOOH和γ-Al₂O₃纳米管均为晶体，代表性长度约为500 nm，直径为20 - 40 nm。γ-Al₂O₃纳米管表现出非常高的介孔比表面积（SSA）为201.0 m² g⁻¹，高介孔体积为0.68 cm³ g⁻¹，平均介孔尺寸为27.7 nm，以及高微孔SSA为186.0 m² g⁻¹，微孔体积为0.08 cm³ g⁻¹，平均微孔尺寸为0.53 nm。讨论了形成过程并提出了一种可能的机理，其中首先由樟脑磺酸根阴离子和Al(III)物种形成层状相，然后在水热条件下卷绕形成晶体纳米管。以乙醇脱水制乙烯作为探针反应测试了所得γ-Al₂O₃纳米管的催化性能，结果表明所得γ-Al₂O₃纳米管催化剂与γ-Al₂O₃纳米颗粒相比具有更高的催化活性。
