Glucose Isomerization into Fructose Catalyzed by MgO/NaY Catalyst

The MgO/NaY catalysts prepared by impregnation method were used for the conversion of glucose to fructose in water medium. The effects of MgO loading, reaction temperature, glucose concentration and reaction time on the catalytic performance for the reaction were studied. The activity testing results indicated that fructose could be generated effectively by controlling the components of the catalyst and reaction conditions. The maximal fructose yield of 33.8% with the selectivity of 67.3% was achieved over the 10%MgO/NaY catalyst at 100 ℃ for 2 h. Moreover, the catalysts were characterized by XRD, BET, and CO2-TPD techniques. The structural property of NaY with higher surface area facilitated glucose conversion, and the modulated basicity of the catalyst with MgO addition contributed to the formation of fructose in the tautornerization of aldose to ketose.

Density Functional Theory Study on Spin States of LaCoO3 at Room Temperature

The electronic structure of the perovskite LaCoO3 at room temperature structure （293 K） was calculated by using PBE, PBE＋U and HSE. Different spin configurations have been considered. Our calculations showed that the choice of the Hubbard U parameter in DFT＋U and mixing factor α in HSE significantly influenced the band gap as well as relative energies. For the spin exited states, the optimal value for U and α were 3.0 eV and 0.05, respectively. Our calculation also emphasized that when U〉5.0 eV, PBE＋U would lead to unreasonable electronic structure and energy order.

P-modified cobalt oxide: A novel and effective catalyst for oxidative dehydrogenation of propane

A series ofnanosized cobalt oxide catalysts modified with phosphorus have been synthesized by the solgel method and investigated in the oxidative dehydrogenation of propane to propene. With the addition of phosphorus, the crystallite size of the catalyst was largely decreased, while the P species in the catalyst were highly dispersed. Compared to pure cobalt oxide, the P-modified samples showed higher propane conversion and enhanced propene selectivity. Over the PCoO catalyst with a P/Co atomic ratio of 0.05, the maximal propene yields of 15.7% with a propane conversion of 28.3% were obtained at 520 ℃.