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There is interest in cultivating an economic and controllable method for preparing biomass-based adsorptive materials for efficient removal of dyes from water. Herein a new bead-like material, i.e. alginate-derived carbon beads with a tailored hierarchical structure and surface chemistry, was prepared by using CaCO3-encapsulated calcium alginate (CA) hydrogel beads as the starting material and subsequent controllable carbonization and oxidation treatment. The resultant samples were characterized by SEM, TEM, FTIR, N2 sorption and XRD, etc. Analyses showed that hierarchical carbon beads with a tailored density of oxygen-containing functional groups have been successfully prepared. Adsorption of methylene blue (MB) was studied systematically through batch and column adsorption analyses, and noting the effect of pH, contact time, initial dye concentrations and flow rates. The adsorption kinetics and isotherms fitted well with the pseudo-second-order kinetic model and Langmuir isotherm model, respectively; and the maximum adsorption capacity for MB was 397.9 mg/g. The results indicated that CaCO3/CA-ox could not only significantly improve the adsorption capacity but also exhibited a higher adsorption rate for MB compared with CA. Furthermore, compared to traditional powdery materials, this bead-like porous adsorbent is convenient for column adsorption and scale-up for practical applications, due to the easy regeneration and reusability. [ABSTRACT FROM AUTHOR]

A layer-by-layer stabilization strategy was employed to immobilize active tungstophosphoric acid onto pentaethylenehexamine-preloaded acidic ZrSBA-15 with short pore channels. The composites were used as catalysts for the deep desulfurization of dibenzothiophene with hydrogen peroxide as green oxidant. The catalyst exhibited excellent desulfurization activity under optimum testing conditions. Moreover, it could be recovered and reused for six reaction runs without a discernible decrease in its activity. [ABSTRACT FROM AUTHOR]

The preparation of Co(II) supported magnetic heterogeneous catalyst, i.e. Fe 3 O 4 @SiO 2 –NH 2 @CS–Co, and its efficient and selective catalytic properties toward the oxidation of ethylbenzene to acetophenone are presented. The materials were characterized by various physicochemical techniques such as scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometer, elemental analysis, inductively coupled plasma-atomic emission spectrometer and X-ray photoelectron spectroscopy, etc. The reaction conditions were thoroughly investigated and highly improved catalytic performance (82.5% conversion of ethylbenzene and 80.1% selectivity to acetophenone) was gained under more mild reaction conditions of lower temperature (70 °C), shorter reaction period (60 min) and cheaper and greener oxygen source (H 2 O 2 ). More importantly, it could be reused successively at least 10 times when more than 80% of its catalytic activity maintained. [ABSTRACT FROM AUTHOR]

A layer-by-layer deposition strategy was employed for the immobilization of tungstophosphoric acid (HPW) onto a pentaethylenehexamine (PEHA)-grafted ZrSBA-15 framework to a give HPW/PEHA/ZrSBA-15 composite. The resulting composite was characterized by XRD, SEM, TEM, FTIR, thermogravimetric analysis, N2 sorption, and X-ray photoelectron spectroscopy, and these methods showed that the composite was stable in polar environments. These properties were attributed to the method of preparation, which ensured that a dense and stable array of HPW was encapsulated within the pores of PEHA-modified ZrSBA-15. In the H2O2-mediated oxidation of benzyl alcohol, the 25 % HPW/PEHA/ZrSBA-15 catalyst exhibited high selectivity (>99 %) for benzaldehyde. Moreover, the oxidation reaction was performed under solvent-free conditions, and the catalyst was recycled several times with negligible loss in selectivity and conversion. This HPW-based catalyst was also efficient at selectively oxidizing other benzylic and alkyl alcohols to the corresponding aldehydes. [ABSTRACT FROM AUTHOR]