H_2在金属钾修饰碳纳米管上的吸附与储存

Hydrogen Storage in Potassium-modified Multiwalled Carbon Nanotubes

利用高压容积法、辅以卸压升温脱附排水法,测定金属钾修饰多壁碳纳米管(K^0-MWCNTs)对H_2的吸附储存容量。结果表明,在室温(～25℃)、～7.25MPa实验条件下其对氢的吸附储存容量可达3.80％(质量百分数);室温下卸至常压的脱附氢量为3.36％(占总吸附氢量的～89％),后续升温(升至673K)的脱附氢量为0.41％(占总吸附氢量的～11％)。

Storage capacity of H2 in a kind of potassium-modified multiwalled carbon nanotubes, K0-MWCNTs, was measured by using high-pressure volumetric method and desorption water-displacement method. It was experimentally shown that appropriate incorporation of a certain amount of metallic potassium into the MWCNTs could significantly increase the storage capacity of hydrogen. Under conditions of 7. 25 MPa pressure and ambient temperature, H2 uptake of 3. 8% can be achieved by K0-MWCNTs, which was as 2. 5 times high as that by the K?undoped MWCNTs under the same conditions. The investigation in combination of the high-pressure volumetric method with the desorption water-displacement method indicated that adsorption of -99% of the H2 was reversible, and that -89% of the stored hydrogen (equalling storage capacities of 3. 36%) could be desorbed while the pressure was relieved to atmospheric pressure and the remaining adsorbed hydrogen (equalling storage capacities of 0. 41%) was desorbed in the following process of elevating temperature from room temperature to 673 K.