题 目:Regulating the catalytic activity of multi-Rubridged polyoxometalates based on differential active site environments with six-coordinate geometry and five-coordinate geometry transitions
作 者:Huafeng Li, Wenjing Chen, Yujie Zhao, Yan Zou, Xue Zhao, Junpeng Song, Pengtao Ma, Jingyang Niu * and Jingping Wang *
刊 名:Nanoscale
年卷页:2021,13,8077-8086.
影响因子：7.790
摘 要：Five-coordinate geometry around ruthenium with highly exposed active sites has attracted intensive scientific interest due to its superior properties and extensive applications. Herein, we report a series of structurally controllable multi-Ru-bridged polyoxometalates, K5NaH10[{Ru4(H2O)n}
(WO2)4(AsW9O33)4]·mH2O {1, 1-dehyd-373K, 1-dehyd-473K, 1-dehyd-573K; n = 4, m = 36; n = 4, m = 6; n = 4, m = 0; n = 0, m = 0} fabricated through a feasible assembly strategy using arsenotungstate {2, KNa12H17Cl2(As4W40O140)·29H2O} as a structure-directing unit. Systematic characterization methods
identified that the six-coordinate geometry can successfully transform into five-coordinate geometry about active sites (Ru) by removing aqua ligands under high reaction temperatures. All the multi-Rubridged polyoxometalates demonstrated strong stability and catalytic effectiveness in the transformation of 1-(4-chlorophenyl)ethanol to 4’-chloroacetophenone under very mild conditions. 1-dehyd-573K, specifically, achieves the best catalytic effectiveness with a turnover frequency (TOF) = 25 100·h−1 owing to its unique five-coordinate geometry on the Ru sites. To our knowledge, 1-dehyd-573K outperforms other POM-based catalysts in the oxidative catalysis of 1-(4-chlorophenyl)ethanol. The heterogeneous polyoxometalates were also proven to be strongly reusable, with their structural integrities well maintained after multiple-cycle catalytic reactions.
文章链接：https://pubs.rsc.org/en/results/journals?Category=journal&AllText=10.1039%2Fd1nr01447a&IncludeReference=false&SelectJournal=True&ArtRefJournalName=Nanoscale%3B&DateRange=false&SelectDate=false&PriceCode=False&OpenAccess=false&JournalName=Nanoscale
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