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[Display omitted] • Novel non-aqueous synthesis of molybdenum silicate microspheres is presented. • The molybdenum silicate microspheres are formed in a one-step condensation process. • Homogeneous distribution of Mo and no MoO 3 phase separation after calcination proved. • High catalytic activity and selectivity in the epoxidation of cyclohexene achieved. • Highly selective catalytic oxidation of aniline to nitrosobenzene observed. In this work, a novel synthesis of homogeneous molybdenum silicate spheres under non-aqueous conditions is presented. A preparation method is based on the condensation of molybdenum metal–organic framework-based precursor solution prepared via a microwave-assisted approach from bis(acetylacetonato)dioxomolybdenum and biphenyl-4,4′-dicarboxylic acid with 3-aminopropyltriethoxysilane under non-aqueous conditions. The as-prepared product was calcined at 500 °C to obtain amorphous and porous molybdenum silicate microspheres with homogeneously distributed molybdenum species within silicate matrix. The microspheres exhibit an average size of about 480 nm. This material was further studied as a heterogeneous catalyst for the epoxidation of olefins via the model catalytic epoxidation of cyclohexene with cumylhydroperoxide. High catalytic activity at the moderate temperature (65 °C) with the conversion of 86% after 2 h and the high selectivity to cyclohexene oxide has been achieved. In addition, molybdenum silicate microspheres exhibit catalytic activity and high selectivity in the oxidation of aniline to nitrosobenzene. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis conditions of iron(II) oxalate particles affect the particles' morphology. • Stirring speed and drip rate influence the ER performance. • Stirring time has negligible effect on the ER performance. • Larger particles tend to electrophoresis while smaller ones not. This study investigates the influence of synthesis conditions of iron(II) oxalate particles on the particle morphology for their utilization in smart materials known as electrorheological (ER) fluids. Particle morphology has a significant impact on the ER behavior of the particles enabling their use in many unique practical applications. In this study, fifteen various iron(II) oxalate particles differing in synthesis conditions were prepared, out of which four variations were selected for an in depth investigation due to their promising morphology. The influence of synthesis conditions on the morphology of the resulted particles was evaluated by scanning electron microscopy analysis. An X-ray diffraction analysis was employed to confirm the dominant FeC 2 O 4 · H 2 O phase presented in the synthesized particles. The ER suspensions consisted of the selected four iron(II) oxalate particles dispersed in silicone oil. An optical microscope and a rheometer, both operating under external electric field, enabled a precise and accurate investigation of the structure, the ER performance. Visual observation was used to evaluate the sedimentation stability of the suspension. [ABSTRACT FROM AUTHOR]

Nickel nanoparticle–decorated reduced graphene oxide nanocomposites (NiG) were prepared by a one-step microwave-assisted solvothermal method. The as-prepared NiG nanocomposite systems were further heated up to 800 °C under an inert atmosphere (named NiG-800) to modify their structural and electromagnetic properties. Thereafter, these developed NiG-800 nanocomposite systems of rGO and nickel nanoparticles (25 wt.%) were applied as nanofillers (50 wt.% and 70 wt.%) in a SEBS (Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene) polymer matrix to create NiG-800(50)-SEBS and NiG-800(70)-SEBS nanocomposites. The addition of NiG-800 to SEBS led to an increase of Young’s modulus from 16 (SEBS) to 35 MPa (NiG-800(70)-SEBS) while the maximum elongation is still around 300%. The developed NiG-800(70)-SEBS nanocomposite exhibited high-performance electromagnetic wave absorption (minimum reflection loss RLmin≈ –48.2 dB at 9.29 GHz) at a low thickness of 2.3 mm in the frequency range of 8.2−12.4 GHz. The prepared NiG-800(70)-SEBS nanocomposite has the potential of an electromagnetic wave absorber. The NiG-800(70)-SEBS nanocomposite reported here has total shielding efficiency > 10 dB at a thickness of 1 mm in the whole frequency range (X-band) with reflection ≈ 50% and absorption ≈ 40% which has the potential for electromagnetic wave absorber applications.

Nowadays, the production of acetaldehyde heavily relies on the petroleum industry. Developing new catalysts for the ethanol dehydrogenation process that could sustainably substitute current acetaldehyde production methods is highly desired. Among the ethanol dehydrogenation catalysts, copper-based materials have been intensively studied. Unfortunately, the Cu-based catalysts suffer from sintering and coking, which lead to rapid deactivation with time-on-stream. Phosphorus doping has been demonstrated to diminish coking in methanol dehydrogenation, fluid catalytic cracking, and ethanol-to-olefin reactions. This work reports a pioneering application of the well-characterized copper phosphinate complexes as molecular precursors for copper-based ethanol dehydrogenation catalysts enriched with phosphate groups (Cu-phosphate/SiO2). Three new catalysts (CuP-1, CuP-2, and CuP-3), prepared by the deposition of complexes {Cu(SAAP)}n(1), [Cu6(BSAAP)6] (2), and [Cu3(NAAP)3] (3) on the surface of commercial SiO2, calcination at 500 °C, and reduction in the stream of the forming gas 5% H2/N2at 400 °C, exhibited unusual properties. First, the catalysts showed a rapid increase in catalytic activity. After reaching the maximum conversion, the catalyst started to deactivate. The unusual behavior could be explained by the presence of the phosphate phase, which made Cu2+reduction more difficult. The phosphorus content gradually decreased during time-on-stream, copper was reduced, and the activity increased. The deactivation of the catalyst could be related to the copper diffusion processes. The most active CuP-1catalyst reaches a maximum of 73% ethanol conversion and over 98% acetaldehyde selectivity at 325 °C and WHSV = 2.37 h–1.

•Facile microwave-assisted synthesis of platelet-like cobalt MOF material reported.•Co-MOF annealing in N2provided porous and magnetic Co@carbon nanocomposite.•Homogeneous Co@carbon nanocomposite with unique morphology of layered discs achieved.•Co-MOF and Co@carbon nanocomposite used as anode materials in Na-Ion batteries.•High performance, low irreversible capacity, and low capacity drop per cycle observed.