(1. 上海大學(xué) 材料科學(xué)與工程學(xué)院，上海 200072；2. 北京科技大學(xué) 冶金與生態(tài)工程學(xué)院，北京 100083)
摘 要: 利用新動(dòng)力學(xué)模型分析了第三組元Co和Fe取代Ni后對(duì)Mg-Mg2Ni吸氫反應(yīng)動(dòng)力學(xué)的影響規(guī)律，探討其吸氫反應(yīng)的控速環(huán)節(jié)，并求解出活化能，同時(shí)驗(yàn)證該新模型同樣適用于該體系的動(dòng)力學(xué)研究。結(jié)果表明：Mg-Mg2Ni1−xMex (Me=Co, Fe; x=0, 0.1, 0.3)氫化反應(yīng)的控速環(huán)節(jié)是氫在氫化物層的擴(kuò)散步驟，Co和Fe取代Ni后對(duì)Mg-Mg2Ni的氫化反應(yīng)速率有影響，但未改變其吸氫反應(yīng)動(dòng)力學(xué)機(jī)制，理論預(yù)報(bào)值與實(shí)驗(yàn)實(shí)測(cè)值較符合；對(duì)于相同吸氫條件，同等取代量的Mg-Mg2Ni1−xCox的特征吸氫時(shí)間比 Mg-Mg2Ni1−xFex的低，說明Co比Fe取代Ni更有利于提高材料的氫化反應(yīng)速率。
關(guān)鍵字: Mg-Mg2Ni1−xMex；儲(chǔ)氫合金；氫化反應(yīng)；動(dòng)力學(xué)
（1. School of Materials Science and Engineering, Shanghai University, Shanghai 200072, China;2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:A new kinetics model proposed was applied to investigate the effect of additives (Co and Fe) on the hydriding kinetic properties of composites based on Mg and Mg2Ni. Much attention was paid to discuss the rate-controlled step, and the reaction activation energy was calculated. The results show that this model is validated by comparison of these calculation results with experimental data. Its kinetic mechanism was well established and its rate-limited step in the hydriding reaction of Mg-Mg2Ni1−xMex composite (Me=Co, Fe; x=0, 0.1, 0.3) is hydrogen diffusion in the metal hydride, which means the additives (Co and Fe) can impose on the hydriding rate without changing the kinetic mechanism of the hydriding reaction. Under the same conditions for hydrogen absorption, the same amount of the additive Co is more profitable to promote the hydriding rate of the composites based on Mg and Mg2Ni than the same amount of the additive Fe on account of the hydriding characteristic time, and the activation energy of the former is smaller than that of the latter.
Key words: Mg-Mg2Ni1−xMex; hydrogen storage alloys; hydriding reaction; kinetic
