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The creation of a catalytic method that possesses high activity and effective reusability for the oxidative cleavage of vegetable oils and their derivatives to prepare bio-based oxo-chemicals is a challenge. This work introduces a “release and capture” catalytic system consisting of H2O2, WO3 and mesoporous SnO2. This system was intended to promote catalyst reusability in the oxidative cleavage of methyl 9,10-epoxystearate (ME) to the corresponding aldehydes. No organic solvent was used in the reaction. The reaction temperature, molar ratio of ME/WO3/H2O2, and reaction time were optimized to 70 °C, 1/0.017/1.3, and 20 min, respectively. Under these conditions, complete ME conversion and 80% aldehyde yield were obtained. The hot filtration experiment and ICP-MS analysis confirmed the leaching of tungsten. Mesoporous SnO2 did not affect the ME conversion and aldehyde yield, but effectively adsorbed the leached tungsten. The catalyst in this system showed no significant decrease in activity after being reused ten times. [ABSTRACT FROM AUTHOR]

Abstract: Sweet sorghum is a high-yielding energy crop that leaves a large amount of lignocellulosic residues after the sugar fraction fermented to ethanol. Here, we developed a biphasic kinetic model for the dilute sulfuric acid-catalyzed hemicellulose hydrolysis of sweet sorghum bagasse at temperatures of 110–150°C, and we then calculated the kinetic parameters for xylose production and furfural decomposition. The results indicated that elevated reaction temperatures promote the hydrolysis of hemicellulose and the degradation of xylose. The xylose yield increased in proportion to reaction time in the initial stages and then declined due to the degradation of xylose to furfural. The pre-exponential factors for the ‘easy-to-hydrolyze’ fraction, the ‘hard-to-hydrolyze’ fraction of hemicellulose and xylose degradation were 3.53×106, 1.80×105 and 0.62min−1, respectively, and the activation energies were 60.7, 58.1 and 14.5kJ/mol, respectively. The ideal hydrolysis condition for xylose production was 140°C for 50min, under which the xylose yield reached 60% of hemicellulose weight. This xylose can be used to form bioethanol and produce further downstream products. [Copyright &y& Elsevier]

The cover picture shows a general strategy to improve the reaction of a typical organic–aqueous heterogeneous green oxidation system, in which surface properties and tunable magnetic nanoparticles were introduced to form a controllable and well‐dispersed emulsion. In their Full Paper, L. Feng et al. reveal that the addition of nanoparticles with proper surface modification can result in improved Montanari reactions compared with the conventional reaction system. The article highlighted by this cover can be found on p. 616 ff. of Issue 4, 2015. [ABSTRACT FROM AUTHOR]