Alapati Sudhakar V, Karl Johnson J, Sholl David S
Department. of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Phys Chem Chem Phys. 2007 Mar 28;9(12):1438-52. doi: 10.1039/b617927d. Epub 2007 Feb 26.
Hydrides of period 2 and 3 elements are promising candidates for hydrogen storage, but typically have heats of reaction that are too high to be of use for fuel cell vehicles. Recent experimental work has focused on destabilizing metal hydrides through mixing metal hydrides with other compounds. A very large number of possible destabilized metal hydride reaction schemes exist, but the thermodynamic data required to assess the enthalpies of these reactions are not available in many cases. We have used density functional theory calculations to predict the reaction enthalpies for more than 300 destabilization reactions that have not previously been reported. The large majority of these reactions are predicted not to be useful for reversible hydrogen storage, having calculated reaction enthalpies that are either too high or too low, and hence these reactions need not be investigated experimentally. Our calculations also identify multiple promising reactions that have large enough hydrogen storage capacities to be useful in practical applications and have reaction thermodynamics that appear to be suitable for use in fuel cell vehicles and are therefore promising candidates for experimental work.
第2和第3周期元素的氢化物是很有前景的储氢候选物，但通常其反应热过高，无法用于燃料电池汽车。最近的实验工作集中在通过将金属氢化物与其他化合物混合来使金属氢化物失稳。存在大量可能的失稳金属氢化物反应方案，但在许多情况下，评估这些反应焓所需的热力学数据并不可得。我们利用密度泛函理论计算预测了300多个此前未报道的失稳反应的反应焓。预计这些反应中的绝大多数对于可逆储氢无用，计算出的反应焓要么过高要么过低，因此这些反应无需进行实验研究。我们的计算还确定了多个有前景的反应，它们具有足够大的储氢容量，可用于实际应用，并且其反应热力学似乎适用于燃料电池汽车，因此是有前景的实验候选对象。
