镁/碳复合纳米材料储氢性能及储氢机理研究

Hydrogen Storage Performance and Mechanism of Magnesium/Carbon Nanocomposites

摘要:

采用反应球磨法，将微晶碳、镁和镍在氢气气氛中反应复合，制备的镁/碳复合材料的纳米晶平均粒度在16.8~33.6 nm。其吸/放氢性能表明，复合材料有很好的储氢动力学和较高的储氢密度，材料70Mg30C4Ni在160 ℃/2 MPa氢气条件下，可以在2 min内完成储氢，储氢密度可达5.0%（质量分数，下同）。XRD物相分析证明，球磨形成的纳米晶镁、纳米碳和催化剂镍三者的协同作用，是复合材料储氢密度增加和动力学性能改善的主要原因。通过红外光谱研究了微晶碳对氢的化学吸附和氢原子在镁/碳复合材料中的传递路径，氢优先被碳吸咐，然后解析传递给镁，且这个过程是可逆的。

Abstract:

Mg/C nanocomposites were compounded of C, Mg and Ni by reaction ball milling in hydrogen. The average size of nano-crystal in the composites is 16.8~33.6 nm. The absorption/desorption hydrogen performances show that the composites possess high reactivity and high hydrogen storage density. In the composite of 70Mg30C4Ni, 5.0 wt% hydrogen can be stored in 2 min at 160 °C and 2 MPa hydrogen pressure. The XRD analysis indicates that the synergistic action of Mg nano-crystal, nano carbon and the catalyst Ni is the main factor to the increase of hydrogen storage density and the improvement of dynamics performance. The chemical adsorption of carbon and pipeline of hydrogen in the Mg/C composite were studied by IR. Hydrogen is absorbed by C with priority and then analyzed to Mg, which is reversible.