Abdel-Mageed Ali M, Rungtaweevoranit Bunyarat, Parlinska-Wojtan Magdalena, Pei Xiaokun, Yaghi Omar M, Behm R Jürgen
Institute of Surface Chemistry and Catalysis , Ulm University , D-89069 Ulm , Germany.
Department of Chemistry and Kavli Energy NanoSciences Institute , University of California-Berkeley , Berkeley , California 94720 , United States.
J Am Chem Soc. 2019 Apr 3;141(13):5201-5210. doi: 10.1021/jacs.8b11386. Epub 2019 Mar 21.
Single-atom catalysts are often considered as the ultimate design principle for supported catalysts, due to their unique geometric and electronic properties and their highly efficient use of precious materials. Here, we report a single-atom catalyst, Cu/UiO-66, prepared by a covalent attachment of Cu atoms to the defect sites at the zirconium oxide clusters of the metal-organic framework (MOF) UiO-66. Kinetic measurements show this catalyst to be highly active and stable under realistic reaction conditions for two important test reactions, the oxidation of CO at temperatures up to 350 °C, which makes this interesting for application in catalytic converters for cars, and for CO removal via selective oxidation of CO in H-rich feed gases, where it shows an excellent selectivity of about 100% for CO oxidation. Time-resolved operando spectroscopy measurements indicate that the activity of the catalyst is associated with atomically dispersed, positively charged ionic Cu species. Density functional theory (DFT) calculations in combination with experimental data show that Cu binds to the MOF by -OH/-OH ligands capping the defect sites at the Zr oxide clusters.
单原子催化剂因其独特的几何和电子性质以及对贵金属材料的高效利用，常被视为负载型催化剂的终极设计原则。在此，我们报道了一种单原子催化剂Cu/UiO-66，它是通过将铜原子共价连接到金属有机框架（MOF）UiO-66的氧化锆簇的缺陷位点上制备而成。动力学测量表明，在实际反应条件下，对于两个重要的测试反应，该催化剂具有高活性和稳定性。在高达350°C的温度下，CO的氧化反应使其在汽车催化转化器应用中具有吸引力；在富氢进料气中通过CO的选择性氧化去除CO时，它对CO氧化显示出约100%的优异选择性。时间分辨原位光谱测量表明，催化剂的活性与原子分散的带正电的离子态铜物种有关。密度泛函理论（DFT）计算结合实验数据表明，Cu通过封端Zr氧化物簇缺陷位点的-OH/-OH配体与MOF结合。
