A green and sustainable approach for biorefining involves the development of bifunctional catalysts for the one-pot conversion of cellulosic biomass to isosorbide. This requires highly efficient, easily separated and versatile metal-acid catalysts for hydrolysis-hydrogenation-dehydration cascade reactions. Herein, we report a new type of metal-acid bifunctional catalyst by dispersing Ru nanoparticles (NPs) on magnetic yolk-shell nanoarchitectures comprising an FeO core and a sulfoacid (SOH)-containing periodic mesoporous organosilica shell. The resultant magnetic Ru-SOH nanoreactors are highly porous and have large surface areas (>350 m g), uniform mesopores (∼3.8 nm), well-dispersed Ru NPs (<1.5 wt%) and superior magnetization. Tailoring the size of the Ru NPs and the amount of SOH moieties produced a highly efficient Ru-SOH nanocatalyst, which delivered a high yield of isosorbide of 58.1% with almost complete conversion of cellulose in 2 h and achieved maximum productivity of 2.19 mol h g, which was one order of magnitude higher than that achieved using other Ru-containing acidic catalysts. Moreover, the elaborately fabricated Ru-SOH nanocatalyst can be easily separated by applying an external magnetic field and can be cycled four times. This work reveals new possibilities for the fabrication of highly efficient, easily separated metal-acid catalysts in virtue of the concept of nanoreactor design.

We herein propose a novel synthetic methodology for a series of nickel-tungsten bimetallics/carbon nanofiber catalysts (Ni, 0.37-2.08 wt%; W, 0.01-0.06 wt%) in situ fabricated by pyrolysis (950°C) of Ni, W and Zn-containing metal organic frameworkThe resulting catalysts (Ni 0.6−x -W x /CNF) have uniform particles (ca. 68 nm), evenly dispersed onto the hierarchically porous carbon nanofibers formed simultaneously. All of the Ni 0.6−x -W x /CNF catalysts prove to be highly active towards direct conversion of cellulose to ethylene glycol (EG). A large productivity ranging from 15.3 to 70.8 mol EG h −1 g W −1 is shown, two orders of magnitude higher than those by using other W-based catalysts reported. † Electronic supplementary information (ESI) available. See

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A new type of carbon nanofiber (CNF) dominated electrode materials decorated with dilute NiO particles (NiO/CNF) has been in situ fabricated by direct pyrolysis of Ni, Zn-containing metal organic framework fibers, which are skillfully constructed by assembling different proportional NiCl 2 •6H 2 O and Zn(Ac) 2 •2H 2 O with trimesic acid in the presence of N,N-dimethylformamide. With elegant combination of advantages of CNF and evenly dispersed NiO particles, as well as successful modulation of conductivity and porosity of final composites, our NiO/CNF composites display well-defined capacitive features. A high capacitance of 14926 F g-1 was obtained in 6 M KOH electrolyte when the contribution from 0.43 wt% NiO was considered alone, contributing to over 35% of the total capacitance (234 F g-1). This significantly exceeds its theoretical specific capacitance of 2584 F g-1. It has been established from the Ragone plot that a largest energy density of 33.4 Wh kg-1 was obtained at the current density of 0.25 A g-1. Furthermore, such composite electrode materials show good rate capability and outstanding cycling stability up to 5000 times (only 10% loss). The present study provides a brand-new approach to design a high capacitance and stable supercapacitor electrode and the concept is extendable to other composite materials.

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