Enhanced hydrogen storage properties of NaBH4-Mg(BH4)2 composites by NdF3 addition

As two important members of complex hydrides, Mg(BH4)(2) and NaBH4 have a high gravimetric capacity (14.9 and 10.8 wt%, respectively). In this study, the Mg(BH4)(2) was synthesized by the ion exchange method. Afterwards, the Mg(BH4)(2) and NaBH4 composites with different amounts (30, 40 and 50 wt%) of NdF3 were prepared by mechanical milling. Effects of the NdF3 on the microstructural evolution and hydrogen storage properties were investigated. The results show that NdF3 catalyst can significantly improve the dehydrogenation kinetics of the eutectic composites of NaBH4-Mg(BH4)(2). The onset hydrogen desorption temperature of the composites is about 88.6 degrees C, which is about 110 degrees C lower than that of Mg(BH4)(2) and NaBH4 composites. Mg(BH4)(2)-NaBH4-0.5NdF(3) composites can released 5.2 wt% H-2 at 250 degrees C within 30 min, and the dehydrogenation capacity is significantly higher than that of Mg(BH4)(2)-NaBH4 composites. The analysis of the dehydrogenation mechanism reveals that NdF3 takes participate in the reaction to generate NaMgF3 to promote the dehydrogenation reaction process of the composites.

Automated summary

In this study, Mg(BH4)(2) was synthesized by the ion exchange method, and Mg(BH4)(2) and NaBH4 composites with different amounts of NdF3 were prepared by mechanical milling. The results show that NdF3 significantly improves the dehydrogenation kinetics and promotes the dehydrogenation reaction process of the composites.