水素の製造と分離を同期した傾斜準結晶膜の開発

本研究的目的是制备一种多功能的梯度结构(梯度膜或纳米合金-金属氧化物偶联)，并探索二十面体结构(Frank-Kasper相和准晶)对不同氧化还原反应催化性能的影响。第一部分研究了Tsai型1/1近似晶体Al-Pd-Sc、Ga-Pd-Sc的催化性能。用无表面氧化的简单C2H2加氢反应评价了这些催化剂的活性和对C2H4的选择性。结果表明，用Al替代Ga可显著提高催化剂的催化活性。密度泛函计算表明，C2H2在Al-Pd-Sc表面的吸附能较高，说明Al-Pd-Sc更有可能吸附气体分子，促进反应。这些结果可以为制备梯度结构的组元的选择提供指导。第二部分研究了与准晶相关的Frank-Kasper相。TCPs中存在大量的二十面体团簇，这些团簇在IQC中是非周期性的，而在TCPs中是三维周期性的。我们的研究表明，二十面体团簇在形成过程中容易产生层错，这为TCP中常见的IQC结构提供了基础。第三部分探讨了Ga/In-Co-Ni/Cu是否可以形成准晶。目前，在这些成分不同的合金中不存在准晶的可能性。

The purpose of this study is to prepare a multifunctional gradient structure (gradient membrane or nanostructured alloy-metal oxide coupling) and explore the influence of icosahedral structure (Frank-Kasper phases and quasicrystals) on catalytic properties of different Oxidation-Reduction Reactions.The main work of this year is divided into three parts. The first part is to study the catalytic properties of Tsai-type 1/1 approximant crystals (ACs) such as Al-Pd-Sc, Ga-Pd-Sc. The activity of these catalysts and their selectivity for C2H4 were evaluated using simple C2H2 hydrogenation reactions with no surface oxidation. It can be found that substituting Ga with Al greatly improves the catalytic activity. DFT calculation shows that the adsorption energy of C2H2 on Al-Pd-Sc surface is higher, indicating that Al-Pd-Sc is more likely to adsorb gas molecules and promote the reaction. These findings can provide guidance for the selection of components in the preparation of gradient structures.In the second part, the Frank-Kasper phases (TCPs) related to quasicrystals is studied. There is a great number of icosahedral clusters in TCPs, and these clusters are aperiodic in IQC, but three-dimensionally periodical in TCPs. Our research indicate that TCPs (icosahedral clusters) are prone to generate stacking fault during formation, which provides a basis for the frequently found IQC structure in the TCPs.The third part explores whether Ga/In-Co-Ni/Cu can form quasicrystals. At present, there is no possibility of quasicrystals in these alloys with different compositions.