title: Fabrication of Ruthenium Nanoparticles in Porous Organic Polymers: Towards Advanced Heterogeneous Catalytic Nanoreactors.
abstract: A novel strategy has been adopted for the construction of a copolymer of benzene-benzylamine-1 (BBA-1), which is a porous organic polymer (POP) with a high BET surface area, through Friedel-Crafts alkylation of benzylamine and benzene by using formaldehyde dimethyl acetal as a cross-linker and anhydrous FeCl3 as a promoter. Ruthenium nanoparticles (Ru NPs) were successfully distributed in the interior cavities of polymers through NaBH4, ethylene glycol, and hydrothermal reduction routes, which delivered Ru-A, Ru-B, and Ru-C materials, respectively, and avoided aggregation of metal NPs. Homogeneous dispersion, the nanoconfinement effect of the polymer, and the oxidation state of Ru NPs were verified by employing TEM, energy-dispersive X-ray spectroscopy mapping, cross polarization magic-angle spinning (13)C NMR spectroscopy, and X-ray photoelectron spectroscopy analytical tools. These three new Ru-based POP materials exhibited excellent catalytic performance in the hydrogenation of nitroarenes at RT (with a reaction time of only ≈ 30 min), with high conversion, selectivity, stability, and recyclability for several catalytic cycles, compared with other traditional materials, such as Ru@C, Ru@SiO2, and Ru@TiO2, but no clear agglomeration or loss of catalytic activity was observed. The high catalytic performance of the ruthenium-based POP materials is due to the synergetic effect of nanoconfinement and electron donation offered by the 3D POP network. DFT calculations showed that hydrogenation of nitrobenzene over the Ru (0001) catalyst surface through a direct reaction pathway is more favorable than that through an indirect reaction pathway.
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore). johncuchem@gmail.com.|Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Uppal Road, Hyderabad-500007 (India). johncuchem@gmail.com.
authors.forename: John
authors.initials: J
authors.lastname: Mondal
authors.affiliation: Department of Materials Science, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India).
authors.forename: Sudipta K
authors.initials: SK
authors.lastname: Kundu
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore).
authors.forename: Wilson Kwok
authors.initials: WK
authors.lastname: Hung Ng
authors.affiliation: Inorganic and Physical Chemistry Division, CSIR-Indian Institute of Chemical Technology (IICT), Uppal Road, Hyderabad-500007 (India).
authors.forename: Ramana
authors.initials: R
authors.lastname: Singuru
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore).
authors.forename: Parijat
authors.initials: P
authors.lastname: Borah
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore). hirao@ntu.edu.sg.
authors.forename: Hajime
authors.initials: H
authors.lastname: Hirao
authors.affiliation: Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore). zhaoyanli@ntu.edu.sg.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Materials Science, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India). msab@iacs.res.in.
authors.forename: Asim
authors.initials: A
authors.lastname: Bhaumik
keywords: density functional calculations; heterogeneous catalysis; hydrogenation; polymers; ruthenium