کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10620636 | 988645 | 2011 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
De-/re-hydrogenation features of NaAlH4 confined exclusively in nanopores
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In the present work, a nanoconfinement system with NaAlH4 exclusively embedded in ordered mesoporous carbon (MC) was synthesized by a three-step procedure, i.e., thermal melting impregnation plus de-/re-hydrogenation. It is demonstrated that the NaAlH4 inside MC shows faster kinetics for dehydrogenation than the kinetics of pristine NaAlH4 with a reduction in activation energy by â¼70Â kJÂ molâ1. An enhanced cycling stability is also achieved by the high-capacity retention of >80% after 15 de-/re-hydrogenation cycles. These remarkable improvements are attributed to the synergistic effects of both nanoconfinement and chemical catalysis caused by the MC, where nanoconfinement plays a dominant role. Furthermore, kinetic modeling studies suggest that the hydrogen release from the confined NaAlH4 system is governed by two processes: the initial process can be expressed by one-dimensional nucleation and growth, and the second process is jointly controlled by three-dimensional diffusion and phase boundary migration.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 59, Issue 4, February 2011, Pages 1829-1838
Journal: Acta Materialia - Volume 59, Issue 4, February 2011, Pages 1829-1838
نویسندگان
Y. Li, G. Zhou, F. Fang, X. Yu, Q. Zhang, L. Ouyang, M. Zhu, D. Sun,