复合储氢材料NaNH2-NaBH4在Ni-Co-B催化剂促进下的热分解

NaNH2 and NaBH4 are structured as a composite hydrogen storage material, NaNH2-NaBH4. To improve the thermal decomposition kinetics of NaNH2-NaBH4, which is crucial to hydrogen releasing performance, Ni-Co-B is selected as a catalyst. To get the catalyst-promoted light-weight hydrogen storage materials, the composite hydrogen storage system was synthesized via a ball milling method with NaNH2, NaBH4 and Ni-Co-B. X-ray diffraction patterns show that the crystal structure of the NaNH2-NaBH4 is well kept after adding catalysts. In addition, Na3BN2 and metal Na are detected as a by-product in the Ni-Co-B promoted NaNH2-NaBH4 (2/1) through the thermal decomposition process. In addition, TG-DTA analysis indicates that the main decomposition stages of the metal boride promoted NaNH2-NaBH4 materials are split into three stages. Furthermore, the catalytic effects on the thermal decomposition kinetics are evaluated. The activation energy of the Ni-Co-B promoted NaNH2-NaBH4 below 250oC is 99KJ/mol, which are only 62.0% of that of the pristine NaNH2-NaBH4 (2/1), and implying better kinetics at low temperature decomposition range.