Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstrasse 3, D-91058 Erlangen, Germany.
Phys Chem Chem Phys. 2012 Aug 14;14(30):10603-12. doi: 10.1039/c2cp40697g. Epub 2012 Jul 3.
Towards a better understanding of the interface chemistry of ionic liquid (IL) thin film catalytic systems we have applied a rigorous surface science model approach. For the first time, a model homogeneous catalyst has been prepared under ultrahigh vacuum conditions. The catalyst, di-μ-chlorobis(chlorotricarbonylruthenium) Ru(CO)(3)Cl(2), and the solvent, the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][Tf(2)N], have been deposited by physical vapor deposition onto an alumina model support [Al(2)O(3)/NiAl(110)]. First, the interaction between thin films of Ru(CO)(3)Cl(2) and the support is investigated. Then, the ruthenium complex is co-deposited with the IL and the influence of the solvent on the catalyst is discussed. D(2)O, which is a model reactant, is further added. Growth, surface interactions, and mutual interactions in the thin films are studied with IRAS in combination with density functional (DFT) calculations. At 105 K, molecular adsorption of Ru(CO)(3)Cl(2) is observed on Al(2)O(3)/NiAl(110). The IRAS spectra of the binary Ru(CO)(3)Cl(2) + [BMIM][Tf(2)N] and ternary Ru(CO)(3)Cl(2) + [BMIM][Tf(2)N] + D(2)O show every characteristic band of the individual components. Above 223 K, partial decomposition of the ruthenium complex leads to species of molecular nature attributed to Ru(CO) and Ru(CO)(2) surface species. Formation of metallic ruthenium clusters occurs above 300 K and the model catalyst decomposes further at higher temperatures. Neither the presence of the IL nor of D(2)O prevents this partial decomposition of Ru(CO)(3)Cl(2) on alumina.
为了更好地理解离子液体（IL）薄膜催化体系的界面化学，我们应用了严格的表面科学模型方法。我们首次在超高真空条件下制备了模型均相催化剂。催化剂二μ-二氯二（氯三羰基钌）Ru(CO)(3)Cl(2)和溶剂 1-丁基-3-甲基咪唑双（三氟甲烷磺酰基）亚胺[BMIM][Tf(2)N]通过物理气相沉积沉积到氧化铝模型载体[Al(2)O(3)/NiAl(110)]上。首先，研究了Ru(CO)(3)Cl(2)薄膜与载体之间的相互作用。然后，共沉积了钌配合物，并讨论了溶剂对催化剂的影响。进一步添加了 D(2)O，这是一种模型反应物。利用红外吸收光谱（IRAS）结合密度泛函（DFT）计算研究了薄膜中的生长、表面相互作用和相互作用。在 105 K 时，观察到Ru(CO)(3)Cl(2)在 Al(2)O(3)/NiAl(110)上的分子吸附。二元Ru(CO)(3)Cl(2)+[BMIM][Tf(2)N]和三元Ru(CO)(3)Cl(2)+[BMIM][Tf(2)N]+D(2)O 的 IRAS 光谱显示了各个组分的每个特征带。在 223 K 以上，部分分解导致了具有分子性质的配合物物种，归因于 Ru(CO)和 Ru(CO)(2)表面物种。在 300 K 以上形成金属钌簇，并且在更高的温度下模型催化剂进一步分解。IL 的存在或 D(2)O 的存在都不能阻止Ru(CO)(3)Cl(2)在氧化铝上的部分分解。
