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以NaH粉和Al粉为合成原料,分别采用2%(摩尔分数,x)CeCl3和2%CeCl3/yKH(y=0.02,0.04)为催化添加剂,在室温和3MPa氢压下,通过反应球磨(NaH/Al+CeCl3)和(NaH/Al+CeCl3/yKH)(y=0.02,0.04)复合物成功制备出Na-Al-H配位氢化物.吸放氢性能测试结果表明,KH的加入能有效改善Na-Al-H体系中第二步脱氢反应放氢动力学性能.(NaH/Al+CeCl3/0.02KH)复合物170°C放氢时可在20min内完成脱氢过程,且在较低温度(100-140°C)下具有良好的可逆吸放氢性能.Kissenger方法计算表明,添加KH可降低Na-Al-H体系第二步脱氢反应的表观活化能,降低其放氢峰值温度.相结构分析表明,KH的添加使Na-Al-H体系中Na3AlH6的晶胞体积发生膨胀,进而提高体系的第二步放氢动力学性能.
NaH powder and Al powder were used as raw materials, respectively, and 2% (molar fraction, x) CeCl3 and 2% CeCl3 / yKH (y = 0.02,0.04) Na-Al-H coordination hydride was prepared successfully by the complex of NaH / Al + CeCl3 and (NaH / Al + CeCl3 / yKH) (y = 0.02,0.04) .The results of hydrogen absorption and desorption performance show that the addition of KH Which can effectively improve the kinetic performance of hydrogen desorption in the second dehydrogenation reaction in Na-Al-H system. (NaH / Al + CeCl3 / 0.02KH) complex dehydrogenation can be completed within 20min at 170 ° C, The reversible hydrogen evolution and desorption performance at low temperature (100-140 ° C) is demonstrated by the Kissenger method, which shows that the addition of KH can reduce the apparent activation energy of the second dehydrogenation reaction in Na-Al-H system, Hydrogen peak temperature.The phase structure analysis showed that the addition of KH expanded the unit cell volume of Na3AlH6 in Na-Al-H system, and then enhanced the kinetic performance of the second-stage hydrogen-desorption.