不同结构的碳纳米管的氢吸附行为

Several kinds of multi-wall carbon nanotubes (MWNTs) with different morphology were synthesized using catalytic decomposition of hydrocarbons over different metal catalysts.The products were characterized by TEM, HREM and SEM. Hydrogen adsorption properties of the MWNTs were investigated by volumetric measurement at room temperature under a modest pressure(6—7 MPa).The results indicate that both the structure of the MWNTs and the metal catalysts will affect the hydrogen adsorption capacity of the sample...     

氢气在大量高纯度定向碳纳米管束中的吸附

Multi-walled carbon nanotubes with uniform diameters and automatically assembled into densely aligned bundles prepared by a bulky yield and high purity were applied as hydrogen absorbant at room temperature under moderate pressure to absorb H_2. Both the surface of nanotubes and the interstitial space among tubes are possible sites for hydrogen molecules to adhere. The hydrogen uptake capacity is 0.82% (mass)and the interstitial position is considered as a promising site for hydrogen absorption.     

Fe/Mo/MgO冻凝胶催化剂大规模合成单壁纳米碳管

通过冷冻干燥法制备了高活性的Fe/Mo/MgO冻凝胶催化剂.在1000℃下用该催化剂催化裂解甲烷,大规模合成了高质量的单壁纳米碳管(SWNTs),利用SEM、TEM、HRTEM、TGA和Raman等分析手段对所制备的SWNTs进行了表征.结果表明,冷冻干燥法制备催化剂合成的粗产品中SWNTs含量高达56wt%,管径分布窄,在0.80～0.95 nm之间,形态以束状为主.Fe/Mo/MgO催化剂极易被酸去除,提纯后的SWNTs纯度高达95%以上.     

超临界干燥法制备催化剂合成单壁纳米碳管及表征

采用超临界干燥法制备了活性高、比表面大的Fe/Mo/Al₂O₃催化剂.通过超临界干燥,催化剂的比表面由294m²/g提高到401m²/g.在1000℃下用该催化剂催化裂解甲烷, 合成了大产量、高质量的单壁纳米碳管(SWNTs).利用SEM、TEM、HRTEM、TGA 和Raman等手段对所制备的SWNTs进行了表征.结果表明:超临界法制备催化剂合成的粗产品中SWNTs含量在30%以上,大大高于同一配方催化剂采用常规干燥法的产率(约2%); SWNTs的管径分布在0.8-1.0nm之间,其形态以束状为主.     

煅烧温度对气凝胶催化剂合成 SWNTs催化活性的影响

研究了不同煅烧温度对Fe／Mo／A12O3气凝胶催化剂合成单壁碳纳米管（SWNTs）催化活性的影响．考察了不同煅烧温度下该催化剂自身的物理化学变化以及催化生长的无定型碳含量，SWNTs的含量、直径及石墨化程度．研究结果表明：不同温度的煅烧处理会影响催化剂的表面形态以及A12O3载体的晶化程度，进而影响了SWNTs的生长．600℃煅烧时，气凝胶催化剂具有最高的活性，此时催化生长的无定型碳含量仅占粗产品的1．7％，SWNTs的含量高达54．6％，且合成的SWNTs质量高、管径分布非常均一，为0．86nm左右．