柠檬酸用量对溶胶凝胶法制备La-Mg储氢合金前躯体微结构的影响研究

Effect of citric acid dosage on microstructure of la-mg hydrogen storage alloy prepared by sol-gel method

本论文利用硝酸镧(La(NO3)3)、硝酸镁(Mg(NO3)2)和柠檬酸的络合反应制备了溶胶凝胶,用红外光谱和扫描电镜对其进行了分析,结果显示随柠檬酸和金属离子摩尔比的提高,制备的溶胶凝胶中羧酸盐的含量随之提高,原因是柠檬酸的羧基在溶液中容易电离形成羧酸根,脱氢后的羟基氧容易与金属离子结合成稳定络合物,这些络合物相互连接构成了三维聚合物框架,形成了羧酸盐。

In this paper by using lanthanum nitrate(La(NO3)3),nitric acid magnesium(Mg(NO3)2)and citric acid complexing reaction was prepared by sol gel,using infrared spectrum and scanning electron microscopy(sem)to analysis,at the same time analyzed the influence of the amount of citric acid on sol gel structure.The results show that with the increase of the molar ratio of citric acid and metal ions,the content of carboxylate in the prepared sol-gel increases accordingly.The reason is that the carboxylate of citric acid is easy to ionize and form carboxylate in the solution,and the hydroxyl oxygen after dehydrogenation is easy to combine with metal ions to form stable complexes.