NaAlH_4分解后的加氢过程  

REHYDROGENATION OF THE DECOMPOSED NaAlH_4

作　　者：方方[1] 张晶[1] 朱健[1] 陈国荣[1] 孙大林[1] C.M.Jensen 

机构地区：[1]复旦大学材料科学系 [2]Department of Chemistry University of Hawaii,Honolulu,HI 96822,USA

出　　处：《金属学报》2007年第1期96-98,共3页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50561206;上海市科委项目045207034资助

摘　　要：采用同步X射线衍射、扫描电镜及颗粒度分析研究了NaAlH4分解后的加氢过程．结果表明,催化剂Ti不仅可以降低NaAlH4的分解温度,也可以将Na3AlH6的分解温度从250℃降至160℃左右．NaAlH4分解后的加氢反应理论上是可逆的,但由于分解后的产物NaH和Al相互分离,尤其是由于聚集所形成的Al颗粒过大,造成Na3AlH6不能全部转变成NaAlH4．这也是导致在随后的吸、放氢循环过程中有效贮氢量降低的原因．进一步的实验表明,当聚集的Al颗粒平均尺寸大于2．3μm时,便不利于加氢过程的完全进行．In situ X-ray diffraction showed that Ti catalyst can reduce not only the dehydrogenation temperature of NaAlH4, but also that of Na3AlH6 from 250℃ to 160℃. The rehydrogenation of the decomposed NaAlH4 is reversible theoretically, but the intermediate hydride, Na3AlH6, is not fully converted into NaAlH4 because of the physical separation of Nail and Al formed in the decomposition, especially the formation of the large Al crystallites. These, therefore, result in a decrease in the hydrogen storage capacity as observed in the following cycling. Additional measurements have showed that those Al crystallites larger than 2.3μm are no longer effective for rehydrogenation.

关 键 词：贮氢材料 NaAlH4 加氢反应 

分 类 号：TG139.7[一般工业技术—材料科学与工程]