(浙江大學(xué) 材料科學(xué)與工程系， 杭州 310027)
摘 要: 采用擴(kuò)散燒結(jié)法制備了Mg2Ni0.75Cr0.25合金， 然后與納米TiO2顆粒混合球磨得到納米復(fù)合材料。 X射線衍射分析結(jié)果表明， 納米復(fù)合材料由Mg2Ni-Ni復(fù)相合金和納米TiO2組成， 平均晶粒度為24~35nm。 納米TiO2顆粒對Mg2Ni0.75Cr0.25合金儲氫動力學(xué)性能的提高具有催化作用， 降低了Mg2Ni0.75Cr0.25合金的吸、 放氫溫度， 使納米復(fù)合材料氫化生成焓明顯降低。 對納米復(fù)合材料的儲氫性能測試結(jié)果表明： 添加1.5%（質(zhì)量分?jǐn)?shù)）TiO2的納米復(fù)合材料在373K、 4MPa下5min內(nèi)完成吸氫， 并在463K、 0.1MPa下20min內(nèi)完成放氫， 最大放氫量為2.57%。
關(guān)鍵字: 儲氫性能； 納米復(fù)合材料； Mg2Ni合金； 納米TiO2
Mg2Ni0.75Cr0.25 alloy by addition of TiO2 nanoparticles
ZHANG Xiao-bin, CHEN Chang-pin
（Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027, China ）
Abstract: The nanocomposites were prepared by ball-milling Mg2Ni0.75Cr0.25 alloy fabricated with different mass fractions (0.5%, 1.5%, 2.5%) of TiO2 nanoparticles. The XRD patterns indicate that the nanocomposites contain Mg2Ni-Ni alloys and TiO2 nanoparticles, and the average crystalline sizes are 24~35nm. The TiO2 nanoparticles can act as catalyst and the nanocomposites show rapid absorption and desorption kinetics, and the absorption and desorption temperatures are greatly decreased. The value of absorption enthalpy for hydride formation of the nanocomposite is decreased as compared with nanocrystalline Mg2Ni0.75Cr0.25 alloy. The absorption of the nanocomposite containing 1.5% TiO2 nanoparticles is almost finished within 5min at 373K under the hydrogen pressure of 4MPa, and desorption is almost finished within 20min at 463K under the hydrogen pressure of 0.1MPa. The nanocomposite gives the hydrogen content of 2.57% under the condition.
Key words: hydrogen storage properties; nanocomposites;
Mg2Ni alloy; TiO2 nanoparticle
