LaAl_(1/3)Fe_(2/3)O_3催化剂的制备及用于VOCs裂解制备碳纳米管

Preparation of LaAl_(1/3)Fe_(2/3)O_3 Catalyst and Its Application to Carbon Nanotubes Synthesis from Volatile Organic Compounds

用硝酸镧、硝酸铝与硝酸铁作原料,采用柠檬酸法制备了多孔铁铝酸镧催化剂,用XRD与SEM对其结构进行表征。采用LaAl1/3Fe2/3O3催化剂,在973K下,研究了易挥发有机物(碳源)苯、环己烷、正己烷、甲苯、甲醇、丙酮催化裂解制备碳纳米管。结果表明,前3种碳源能高收率制备管径均匀的碳纳米管;甲苯、丙酮裂解得到少量不均匀的碳纳米管;甲醇裂解没有碳纳米管生成。以环己烷为碳源,研究了裂解温度对碳纳米管生成的影响,采用SEM、TEM表征了碳纳米管的形貌。

LaAl_(1/3)Fe_(2/3)O_3 catalyst was synthesized by the citrate method with La(NO_3)_3·6H_2O,Al(NO_3)_3·3H_2O,Fe(NO_3)_3·9H_2O and citric acid as raw materials.Its structure was characterized by means of X-ray diffraction and scanning electron microscopy(SEM).Effects of volatile organic compounds as carbon sources on carbon nanotubes synthesies were studied using LaAl_(1/3)Fe_(2/3)O_3 catalyst at 973 K.Carbon nanotubes of high yield and uniformity can be obtained from catalytic decomposition of benzene,cycohexane and n-hexane.Carbon nanotubes of low yield can be obtained from catalytic decomposition of toluene and acetone.When methanol used as carbon sources,it was difficult to synthesize carbon nanotube.Effects of decomposition temperatures on the carbon nanotubes synthesies by catalytic decomposition of cycohexane were studied.Morphological structures of the carbon nanotubes were characterized by SEM and TEM.