Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Faraday Discuss. 2017 Sep 1;201:287-302. doi: 10.1039/c7fd00055c. Epub 2017 Jun 20.
NU-1000, a mesoporous metal-organic framework (MOF) featuring hexazirconium oxide nodes and 3 nm wide channels, was infiltrated with a reactive dicobalt complex to install dicobalt active sites onto the MOF nodes. The anchoring of the dicobalt complex onto NU-1000 occurred with a nearly ideal stoichiometry of one bimetallic complex per node and with the cobalt evenly distributed throughout the MOF particle. To access thermally robust multimetallic sites on an all-inorganic support, the modified NU-1000 materials containing either the dicobalt complex, or an analogous cobalt-aluminum species, were nanocast with silica. The resulting materials feature Co or Co-Al bimetallated hexazirconium oxide clusters within a silica matrix. The cobalt-containing materials are competent catalysts for the selective oxidation of benzyl alcohol to benzaldehyde. Catalytic activity depends on the number of cobalt ions per node, but does not vary significantly between the NU-1000 and silica supports. Hence, the multimetallic oxide clusters remain site-isolated and substrate-accessible within the nanocast materials.
NU-1000 是一种具有六氧化二钴节点和 3nm 宽通道的介孔金属有机骨架（MOF），用反应性二钴配合物渗透，将二钴活性位点安装到 MOF 节点上。二钴配合物在 NU-1000 上的锚定几乎具有每个节点一个双金属配合物的理想化学计量比，并且钴均匀分布在整个 MOF 颗粒中。为了在全无机载体上获得热稳定的多金属位点，用二氧化硅对含有二钴配合物或类似的钴-铝物种的改性 NU-1000 材料进行纳米铸造。所得材料在二氧化硅基质内具有 Co 或 Co-Al 双金属化六氧化二钴簇。含钴材料是苄醇选择性氧化为苯甲醛的有效催化剂。催化活性取决于每个节点的钴离子数，但在 NU-1000 和二氧化硅载体之间变化不大。因此，多金属氧化物簇在纳米铸造材料中仍然保持位隔离和底物可及性。
