Instituto de Ciencias Aplicadas y Tecnología (UNAM); Facultad de Ciencias (UNAM), Universidad Nacional Autónoma de México, Circuito Exterior S/N, Ciudad Universitaria, 04510, México City, México.
Instituto de Ciencias Aplicadas y Tecnología (UNAM).
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 5;284:121776. doi: 10.1016/j.saa.2022.121776. Epub 2022 Aug 23.
Ammonia borane, as a source of hydrogen, has attracted much attention due to its high hydrogen content, low molecular weight, and high stability in solution. However, the process and enhancement of hydrogen release must be done practically under ambient conditions. For this work, Raman spectroscopy, principal component analysis (PCA), and molecular simulation were applied to study the hydrogen release process of ammonia borane. Three stages of release were observed from room temperature to 1300 °C. The shift, the appearance, and the disappearance of the Raman bands were evident in the whole process. In-situ monitoring of Raman and PCA, with four different heating rates between 70 and 130 °C, was done; ammonia borane showed visible variations in its first release step, in which a fast rate helped reduce distortion in the release process. Finally, molecular simulation of ammonia borane using the Density Functional Theory (DFT) in calculations showed that dihedral rotation and stretching of the hydrogen bonds can occur before the first release step.
硼烷氨作为一种储氢材料，由于其具有高含氢量、低分子量和在溶液中的高稳定性而受到广泛关注。然而，必须在环境条件下实际进行氢气释放的过程和增强。在这项工作中，拉曼光谱、主成分分析（PCA）和分子模拟被应用于研究硼烷氨的氢气释放过程。从室温到 1300°C 观察到三个释放阶段。在整个过程中，拉曼带的位移、出现和消失都很明显。对拉曼和 PCA 进行了原位监测，加热速率在 70 到 130°C 之间有四种不同，硼烷氨在其第一步释放中表现出明显的变化，快速的释放速率有助于减少释放过程中的变形。最后，使用密度泛函理论（DFT）在计算中对硼烷氨进行分子模拟表明，在第一步释放之前可以发生二面角旋转和氢键的拉伸。
