pH值及助剂对氢化态Mg-Mn复合物水反应性能的影响

Influence of pH value and additives on water reaction performance of hydrogenated Mg-Mn composites

为了提高氢化态Mg-Mn复合物的水反应性能,采用改变反应水溶液pH值和在水溶液中加入不同助剂的方法,通过测量反应过程中不同时刻产生的氢气量对助剂在水反应中的作用进行表征,利用SEM和XRD等测试手段对反应产物进行表征和测试,对反应机理进行分析。结果表明:改变反应溶液的pH值对反应程度及放氢速率的影响不大,且pH值越大,越不利于反应的进行;在溶液中添加助剂焦磷酸钾、六偏磷酸钠、羟基乙叉二膦酸(HEDP)对提高氢化态Mg-Mn复合物的放氢速率有显著促进作用;相比之下,应采用添加磷酸盐助剂的方法来改善氢化态Mg-Mn复合物水反应性能。

In order to improve the water reaction performance of hydrogenated Mg-Mn composites, the pH value of the hydrolysis solution was changed and different additives were added in the solution. The amount of hydrogen produced by different kinds of samples was used to characterize the hydrolysis reactivity. SEM, XRD and other testing methods were used to characterize and test the hydrolysis products. The reaction mechanism was analyzed. The results show that changing the pH value of the reaction solution has a little influence on the hydrolysis rate and the reaction degree, and the higher the pH value, the more disadvantageous the reaction. The addition of additives of the potassium pyrophosphate, sodium hexametaphosphate and HEDP plays a significant role in promoting the hydrogen desorption rate. In contrast, the method of adding phosphate additives should be used to improve the water-reactive properties of the hydrogenated Mg-Mn composites.