Controlled Catalytic Energy Release of the Norbornadiene/Quadricyclane Molecular Solar Thermal Energy Storage System on Ni(111)
Controlled Catalytic Energy Release of the Norbornadiene/Quadricyclane Molecular Solar Thermal Energy Storage System on Ni(111)
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DOI：
10.1021/acs.jpcc.8b03746
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发表时间：
2019-04-04
影响因子：
3.7
通讯作者：
Papp, C.
中科院分区：
文献类型：
--
作者：
Bauer, U.;Fromm, L.;Papp, C.
研究了Ni（111）上降冰片二烯(NBD)/四环烷（QC）价同分异构体对的分子太阳能储能系统的表面化学性质。我们的多方法方法包括紫外光电子能谱（UPS）、高分辨率x射线光电子能谱（XPS）、近边缘x射线吸收精细结构（NEXAFS）和密度泛函理论（DFT）计算。由于NBD/QC系统具有相当高的重力储能密度，并且在催化和可持续循环中释放能量，因此具有在未来储能技术中应用的潜力。UPS显示两种化合物在120 K时的分子吸附，这也是DFT预测的。NEXAFS和DFT表明，NBD的吸附几何形状是两个双键与表面结合(eta（2):eta(2)）。对于QC，没有发现偏好，并且eta(2):eta(2)和eta(2):eta(1)的吸附几何都是稳定的。QC到NBD的转换是热激活的。从UPS中，确定了类似175k的反应温度。用XPS研究了NBD可能发生的有害分解反应。在190k时，苯（C6H6）和甲基乙炔（CH）生成，并在330k时进一步与C-H片段反应，最终在475 K以上的表面留下碳化物。
We have investigated the surface chemistry of the molecular solar thermal energy storage system of the valence isomer pair norbornadiene (NBD)/quadricyclane (QC) on Ni(111). Our multimethod approach includes UV-photoelectron spectroscopy (UPS), high-resolution X-ray photoelectron spectroscopy (XPS), near edge X-ray absorption fine structure (NEXAFS), and density functional theory (DFT) calculations. The NBD/QC system holds the potential to be utilized in future energy storage technologies due to its comparably high gravimetric energy storage density, and the release of energy in a catalytic and sustainable cycle. UPS shows molecular adsorption of both compounds at 120 K, as is also predicted by DFT. NEXAFS and DFT suggest an adsorption geometry of NBD with both double bonds binding to the surface (eta(2):eta(2)). For QC, no preference is found, and both the eta(2):eta(2) and the eta(2):eta(1) adsorption geometry are stable. The conversion of QC to NBD is thermally activated. From UPS, a reaction temperature of similar to 175 K is determined. Possible detrimental decomposition reactions of NBD were investigated by XPS. At 190 K, benzene (C6H6) and methylidyne (CH) are formed, and further react to C-H fragments at 330 K and finally leave carbide on the surface above 475 K.