锰结核矿物及其原位复合材料吸氢性能的初步研究

A PRELIMINARY STUDY ON HYDROGEN-ABSORBING CAPABILITY OF MARINE MANGANESE NODULES AND THEIR COMPOSITE MATERIALS

采自东太平洋中国开辟区的锰结核 ,主矿物相为钡镁锰矿、钠水锰矿 ,以及属XRD隐晶质的针铁矿与四方纤铁矿 ,部分矿物相结构特征与人工合成的纳米碳管十分相似。在室温中压下采用等容压差法测量了锰结核的气态贮氢能力 ,测得锰结核样品的吸氢量为 0 .3 1 %。以乙炔为碳源 ,在 75 0℃下采用气相沉积法直接在锰结核上成功地催化制备出多壁纳米碳管和纳米碳纤维 ,同样条件测试这种矿物碳管原位复合材料的吸氢性能 ,其吸氢能力达到 1 %左右。保持锰结核矿物结晶结构在加热脱水过程中的稳定性 ,对提高其贮氢能力至关重要。

Manganese nodules collected from the China's Pioneer Area in the East Pacific are composed mainly of delatorreite and Na manganite, and subordinately of goethite and akaganeite. The microstructural features of some mineral species are similar to those of carbon nanotubes. The gaseous hydrogen storage capacity of the minerals was measured by pressure drop in the sample chamber under moderate pressure at room temperature. The hydrogen storage capacity of the minerals was found to be 0.31 wt%. Multi walled carbon nanotubes and graphite nanofibers could be successfully synthesized on the powder of manganese nodules directly by chemical vapor deposition at 750℃. The hydrogen storage capability of the composite minerals with carbon nanomaterials was around 1.0 wt%, measured under the same conditions. How to keep the tunnel structure stable during dehydration is essential for improving the hydrogen storage capacity of manganese nodule minerals.