本實驗的研究目的為進一步提高Mg23.5Ni共晶合金的儲氫特性，並探討催化劑與球磨時間對合金儲氫性能之影響。 實驗時以傳統熔煉法製備Mg23.5Ni共晶合金，以XRD及EPMA等儀器對合金的金相及化學成份進行分析。结果顯示，以傳統熔煉法所製備的Mg23.5Ni共晶合金，在金相及化學成份結果上均與理論值接近。Mg23.5Ni+5 wt％x-catalysts（x=C(Pd),Nb2O5,Y2O3）合金利用高能量的SPEX 8000球磨機所合成，並討論球磨與催化劑（C(Pd),Nb2O5,Y2O3）對Mg23.5Ni共晶合金吸放氫特性之影響。研究中發現C(Pd)在Mg23.5Ni共晶合金吸放氫特性以及降低吸收焓之改善上比其他催化劑有更理想的效果。 合金顆粒尺寸减小能有效提高合金吸放氫速率，並降低Mg23.5Ni共晶合金的吸收焓。另外，結果亦顯示合金吸收焓降低與 Mg23.5Ni共晶合金吸氫速率提高有直接關係。 The objectives of this work are to further enhance the hydrogen properties of Mg-23.5Ni eutectic alloy, and to investigate the impact of catalysts and milling time on the hydrogen storage properties. Mg23.5Ni eutectic alloy, as raw material, was produced by conventional melting. Phases and chemical compositions were evaluated by XRD and EPMA. The results show that the phases and chemical composition of as-prepared Mg23.5Ni is nearly the same with theoretical composition. Mg23.5Ni+5wt% x-catalysts (x= C(Pd), Nb2O5, Y2O3) alloys were synthesized by using high-energy SPEX 8000 shaker mill. The effects of mechanical milling and x-catalysts (x= C(Pd), Nb2O5, Y2O3) on the hydriding and dehydriding properties of Mg23.5Ni eutectic alloys are discussed. It was found that C(Pd) is more effective than the others catalysts in improving the hydriding-dehydriding properties of Mg23.5Ni eutectic alloy as well as decreasing the absorption enthalpy. The decreasing of particle size leads to improving in the hydrogen absorption-desorption rate and is decreasing the absorption enthalpy of Mg23.5Ni eutectic alloy. It shows that the decreasing of absorption enthalpy has directly relation to increasing the hydrogen absorption rate of Mg23.5Ni eutectic alloy.
