In situ synthesis of sub-nanometer metal particles on hierarchically porous metal-organic frameworks via interfacial control for highly efficient catalysis

Pei Zhang; Chunjun Chen; Xinchen Kang; Lujun Zhang; Congyi Wu; Jianling Zhang; Buxing Han

doi:10.1039/c7sc04269h

In situ synthesis of sub-nanometer metal particles on hierarchically porous metal-organic frameworks via interfacial control for highly efficient catalysis

Chem Sci. 2017 Dec 14;9(5):1339-1343. doi: 10.1039/c7sc04269h. eCollection 2018 Feb 7.

Authors

Pei Zhang^{1

2}, Chunjun Chen^{1

2}, Xinchen Kang^{1

2}, Lujun Zhang^{1

2}, Congyi Wu¹, Jianling Zhang^{1

2}, Buxing Han^{1

2}

Affiliations

¹ Beijing National Laboratory for Molecular Sciences , Key Laboratory of Colloid and Interface and Thermodynamics , Institute of Chemistry , Chinese Academy of Sciences , Beijing 100190 , P. R. China . Email: hanbx@iccas.ac.cn.
² University of Chinese Academy of Sciences , Beijing 100049 , P. R. China.

Abstract

In this work, we developed a strategy to in situ synthesize sub-nanometer metal particle/hierarchically mesoporous metal-organic framework (MOF) composites in emulsion. In this route, water droplets in the emulsion acted as both a solvent of the metal precursors and a template for the hierarchical mesopores of MOFs, and the surfactant was an emulsifier and a reductant for generating metal particles. Au/Zn-MOFs (MOFs formed by Zn²⁺ and methylimidazole), Ru/Zn-MOFs, Pd/Zn-MOFs, and Au/Cu-MOFs (MOFs formed by Cu²⁺ and methylimidazole) were prepared using this method, in which ultrafine metal particles (e.g. 0.8 nm) were immobilized uniformly on hierarchically mesoporous MOFs. Au/Zn-MOFs and Au/Cu-MOFs showed outstanding catalytic performances for the selective aerobic oxidation of cyclohexene to 2-cyclohexen-1-one in the absence of an initiator, and Ru/Zn-MOFs were very active and selective for the hydrogenation of diphenyl sulfoxide to diphenyl sulfide. In addition, the catalysts were also very stable in the reactions.