For the first time,the MgH_(2)–NaAlH_(4)(ratio 4:1)destabilized system with CoTiO_(3) addition has been explored.The CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample begins to dehydrogenate at 130℃,which is declined by 40...For the first time,the MgH_(2)–NaAlH_(4)(ratio 4:1)destabilized system with CoTiO_(3) addition has been explored.The CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample begins to dehydrogenate at 130℃,which is declined by 40℃ compared to the undoped MgH_(2)–NaAlH_(4).Moreover,the de/rehydrogenation kinetics characteristics of the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) were greatly ameliorated.With the inclusion of CoTiO_(3),the MgH_(2)–NaAlH_(4) composite absorbed 5.2 wt.%H_(2),higher than undoped MgH_(2)–NaAlH_(4).In the context of dehydrogenation,the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample desorbed 2.6 wt.%H_(2),almost doubled compared to the amount of hydrogen desorbed from the undoped MgH_(2)–NaAlH_(4) sample.The activation energy obtained by the Kissinger analysis for MgH_(2) decomposition was significantly lower by 35.9 kJ/mol than the undoped MgH_(2)–NaAlH_(4) sample.The reaction mechanism demonstrated that new phases of MgCo and AlTi_(3) were generated in situ during the heating process and are likely to play a substantial catalytic function and be useful in ameliorating the de/rehydrogenation properties of the destabilized MgH_(2)–NaAlH_(4) system with the inclusion of CoTiO_(3).展开更多
TiC-doped NaA1H4 complex hydrides were prepared by hydrogenation of ball-milled Nail/A1 mixture with x TiC powder （x = 0, 5%, 8%, 10%, mole fraction）. The effects of TiC catalyst content on the absorption/desorption...TiC-doped NaA1H4 complex hydrides were prepared by hydrogenation of ball-milled Nail/A1 mixture with x TiC powder （x = 0, 5%, 8%, 10%, mole fraction）. The effects of TiC catalyst content on the absorption/desorption behaviors of the samples were investigated. The results show that TiC can improve the hydriding/dehydriding kinetics of sodium aluminum hydride, the hydriding rate of the sample increases with increasing TiC content. It is found that the TiC-doped NaA1H4 composites have a relatively good cyclic stability. The composite doped with 10% TiC maintains steadily about 4.5% （mass fraction） hydrogen absorption capacity as against about 3.8% （mass fraction） hydrogen desorption capacity over 8 cycles. The particle sizes of the TiC-doped NaA1H4 composites can be reduced to 50-100 nm, which may play an important role in improving the hydriding/dehydriding kinetics.展开更多
The Bells是一首四节不规则颂诗,连续讲述人生的不同阶段;每一节都有它自己的金属钟声:雪橇的银铃、婚礼的金钟、铜的警钟和铁的丧钟。这四种钟声分别表达了作者对每一个人生阶段的不同态度。"音必须像是义的回音",作者对音...The Bells是一首四节不规则颂诗,连续讲述人生的不同阶段;每一节都有它自己的金属钟声:雪橇的银铃、婚礼的金钟、铜的警钟和铁的丧钟。这四种钟声分别表达了作者对每一个人生阶段的不同态度。"音必须像是义的回音",作者对音素的使用成功地表达了想要表达的思想感情。展开更多
基金supported by the Research Intensified Grant Scheme (RIGS) under grant number VOT 55440 provided by Universiti Malaysia Terengganu (UMT)the SIPP Incentive sponsored by UMT
文摘For the first time,the MgH_(2)–NaAlH_(4)(ratio 4:1)destabilized system with CoTiO_(3) addition has been explored.The CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample begins to dehydrogenate at 130℃,which is declined by 40℃ compared to the undoped MgH_(2)–NaAlH_(4).Moreover,the de/rehydrogenation kinetics characteristics of the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) were greatly ameliorated.With the inclusion of CoTiO_(3),the MgH_(2)–NaAlH_(4) composite absorbed 5.2 wt.%H_(2),higher than undoped MgH_(2)–NaAlH_(4).In the context of dehydrogenation,the CoTiO_(3)-doped MgH_(2)–NaAlH_(4) sample desorbed 2.6 wt.%H_(2),almost doubled compared to the amount of hydrogen desorbed from the undoped MgH_(2)–NaAlH_(4) sample.The activation energy obtained by the Kissinger analysis for MgH_(2) decomposition was significantly lower by 35.9 kJ/mol than the undoped MgH_(2)–NaAlH_(4) sample.The reaction mechanism demonstrated that new phases of MgCo and AlTi_(3) were generated in situ during the heating process and are likely to play a substantial catalytic function and be useful in ameliorating the de/rehydrogenation properties of the destabilized MgH_(2)–NaAlH_(4) system with the inclusion of CoTiO_(3).
基金Project(2010CB631300)supported by the National Basic Research Program of ChinaProjects(50871099,51001090)supported by the National Natural Science Foundation of China+1 种基金Projects(20080440196,200902622)supported by the China Postdoctoral Science FoundationProject(20090101110050)supported by the University Doctoral Foundation of the Ministry of Education,China
文摘TiC-doped NaA1H4 complex hydrides were prepared by hydrogenation of ball-milled Nail/A1 mixture with x TiC powder （x = 0, 5%, 8%, 10%, mole fraction）. The effects of TiC catalyst content on the absorption/desorption behaviors of the samples were investigated. The results show that TiC can improve the hydriding/dehydriding kinetics of sodium aluminum hydride, the hydriding rate of the sample increases with increasing TiC content. It is found that the TiC-doped NaA1H4 composites have a relatively good cyclic stability. The composite doped with 10% TiC maintains steadily about 4.5% （mass fraction） hydrogen absorption capacity as against about 3.8% （mass fraction） hydrogen desorption capacity over 8 cycles. The particle sizes of the TiC-doped NaA1H4 composites can be reduced to 50-100 nm, which may play an important role in improving the hydriding/dehydriding kinetics.
