原位X射线衍射表明催化剂Ti不仅可降低NaAlH4的分解温度，也可将Na3AlH6的分解温度从250 ℃降低至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。进一步的实验发现，当聚集的Al颗粒平均尺寸大于2.3 µm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 NaH 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 2.3 µm are no longer effective for rehydrogenatrion.
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