添加剂CeO_2对La_2Mg_(17)-50% Ni储氢性能的影响

Catalytic Effect of CeO_2 on Hydriding/dehydriding Properties of La_2Mg_(17)-50% Ni Alloy

研究了球磨添加CeO2对La2Mg17-50%(质量分数,下同)Ni复合合金的相结构和储氢性能的影响,并对合金的形貌和吸放氢性能进行了检测。XRD结果表明,球磨加入CeO2后,在La2Mg17-50%Ni合金中除了Mg2Ni和Ni相外,产生Ce Mg12相。SEM形貌图清晰地看见CeO2附在La2Mg17-50%Ni合金表面上呈白色小颗粒。吸氢动力学性能表明,加入CeO2后,使La2Mg17-50%Ni合金的最大吸氢量从3.298%增加到3.594%。添加CeO2后合金的最佳饱和吸氢温度降为200℃(3 MPa),且吸氢动力学性能提高至1 min内的吸氢量达到3.382%,是其最大吸氢量的94%。然而,CeO2在放氢过程中的积极作用并不明显。

In order to explore the catalytic effect of CeO2 on hydriding and dehydriding process of La2 Mg17 -50% （mass fraction） alloys, the phase structure and morphology have been investigated. XRD results indicated that the addition of CeO2 brings CeMgn phase, except of Mg2 Ni and Ni phase. SEM image indicated that the white small particles attached on the sur- face were Ce element. The hydriding experiments exhibited that the addition of CeO2 improved the maximum hydrogen capacity from 3. 298 % to 3. 594 %, and reduced the optimum hydrogenation temperature to 200℃ under 3MPa. The hydrogen absorp- tion kinetics reached to 5. 382% in 1 rain, representing 94% of the maximum value. However, the effect of CeO2 on dehydriding process is not ideal.