Strobel Timothy A, Kim Yongkwan, Andrews Gary S, Ferrell Jack R, Koh Carolyn A, Herring Andrew M, Sloan E Dendy
Chemical Engineering Department, Colorado School of Mines, Golden, Colorado 80401, USA.
J Am Chem Soc. 2008 Nov 12;130(45):14975-7. doi: 10.1021/ja805492n. Epub 2008 Oct 17.
Hydrogen storage from two independent sources of the same material represents a novel approach to the hydrogen storage problem, yielding storage capacities greater than either of the individual constituents. Here we report a novel hydrogen storage scheme in which recoverable hydrogen is stored molecularly within clathrate cavities as well as chemically in the clathrate host material. X-ray diffraction and Raman spectroscopic measurements confirm the formation of beta-hydroquinone (beta-HQ) clathrate with molecular hydrogen. Hydrogen within the beta-HQ clathrate vibrates at considerably lower frequency than hydrogen in the free gaseous phase and rotates nondegenerately with splitting comparable to the rotational constant. Compared with water-based clathrate hydrate phases, the beta-HQ+H2 clathrate shows remarkable stability over a range of p-T conditions. Subsequent to clathrate decomposition, the host HQ was used to directly power a PEM fuel cell. With one H2 molecule per cavity, 0.61 wt % hydrogen may be stored in the beta-HQ clathrate cavities. When this amount is combined with complete dehydrogenation of the host hydroxyl hydrogens, the maximum hydrogen storage capacity increases nearly 300% to 2.43 wt %.
利用同一材料的两种独立来源进行储氢是解决储氢问题的一种新方法，其储氢容量大于任何一种单独成分的储氢容量。在此，我们报道了一种新型储氢方案，其中可回收的氢以分子形式存储在笼形包合物的笼腔内，并以化学方式存储在笼形包合物主体材料中。X射线衍射和拉曼光谱测量证实了与分子氢形成了β - 对苯二酚（β - HQ）笼形包合物。β - HQ笼形包合物中的氢振动频率远低于自由气相中的氢，并且以与转动常数相当的分裂进行非简并转动。与水基金属笼形水合物相相比，β - HQ + H₂笼形包合物在一系列p - T条件下表现出显著的稳定性。笼形包合物分解后，主体HQ被直接用于为质子交换膜燃料电池供电。每个笼腔中有一个H₂分子时，β - HQ笼形包合物的笼腔中可存储0.61 wt%的氢。当这一量与主体羟基氢的完全脱氢相结合时，最大储氢容量增加近300%，达到2.43 wt%。
