Department of Chemistry, University of California-Berkeley, Kavli Energy NanoSciences Institute , Berkeley, California 94720, United States.
Materials Metrology Division, National Institute of Metrology, Quality, and Technology , Duque de Caxias, Rio de Janeiro 25250-020, Brazil.
Nano Lett. 2016 Dec 14;16(12):7645-7649. doi: 10.1021/acs.nanolett.6b03637. Epub 2016 Nov 7.
We show that the activity and selectivity of Cu catalyst can be promoted by a Zr-based metal-organic framework (MOF), ZrO(OH)(BDC) (BDC = 1,4-benzenedicarboxylate), UiO-66, to have a strong interaction with Zr oxide [ZrO(OH)(-CO)] secondary building units (SBUs) of the MOF for CO hydrogenation to methanol. These interesting features are achieved by a catalyst composed of 18 nm single Cu nanocrystal (NC) encapsulated within single crystal UiO-66 (Cu⊂UiO-66). The performance of this catalyst construct exceeds the benchmark Cu/ZnO/AlO catalyst and gives a steady 8-fold enhanced yield and 100% selectivity for methanol. The X-ray photoelectron spectroscopy data obtained on the surface of the catalyst show that Zr 3d binding energy is shifted toward lower oxidation state in the presence of Cu NC, suggesting that there is a strong interaction between Cu NC and Zr oxide SBUs of the MOF to make a highly active Cu catalyst.
我们证明，Zr 基金属-有机骨架（MOF）ZrO(OH)(BDC)（BDC=1,4-苯二甲酸）UiO-66 可促进 Cu 催化剂的活性和选择性，与 MOF 的 Zr 氧化物[ZrO(OH)(-CO)]次级建筑单元（SBU）具有很强的相互作用，从而促进 CO 向甲醇的加氢反应。这些有趣的特性是通过由 18nm 单 Cu 纳米晶体（NC）封装在单晶 UiO-66 内的催化剂（Cu⊂UiO-66）实现的。该催化剂结构的性能超过了基准 Cu/ZnO/AlO 催化剂，甲醇的产率稳定提高 8 倍，选择性达到 100%。在催化剂表面获得的 X 射线光电子能谱数据表明，Zr 3d 结合能在 Cu NC 的存在下向较低的氧化态偏移，这表明 Cu NC 和 MOF 的 Zr 氧化物 SBU 之间存在很强的相互作用，从而形成了高活性的 Cu 催化剂。
