Electrocatalytic Synthesis of Propylene Carbonate from CO_2 and Propylene Oxide

The electrocatalytic synthesis of propylene carbonate（PC） from CO2 and propylene oxide（PO） was studied under mild conditions（PCO2=1.01×105 Pa, t=25 ℃）. Influences of solvents, supporting electrolytes, the passed charge, the nature of electrodes and the current density（j） on the yield of PC were investigated to optimize the electrolytic conditions, with the maximal yield to be 46.2%, the selectivity of propylene carbonate is 100%. The reduction of propylene oxide in the absence and presence of CO2 was examined by cyclic voltammetry. The mechanism of the reaction initiated by the synergistic effect of halides ions of supporting electrolytes with nucleophilicity and the metal ions from scarification anode with Lewis acid acidity was proposed on the basis of our results.

Electrocarboxylation of Anthrone to Anthracene-9-carboxylic Acid in the Presence of CO_2

Electrocarboxylation of anthrone in the presence of CO2 to anthrance-9-carboxylic acid directly was carried out. The electroreduction behavior of anthrone was examined by cyclic voltammetry in the absence and presence of CO2. Then the influences of the supporting electrolytes, temperature, electrode material and anthrone concentration on the carboxylation yield were investigated. Under the optimized conditions, anthrancene-9-carboxylic acid was obtained in a good yield（96.1%）.

Mineral phase reconstruction behavior of direct reduction and smelting titanium slag at high temperature and slow cooling

Titanium slag in this study was produced by subjecting titanomagnetite concentrate to direct reductionelectric furnace smelting. Processing mineralogy and mineral phase reconstruction behavior at high temperature and slow cooling treatment were examined by chemical analysis, X-ray diffraction （XRD）, optical microscopy （OM）, scanning electron microscopy （SEM）, and energydispersive spectroscopy （EDS）. Anosovite solid solution is the main titanium product by the direct reduction and smelting process. Results of slow-cooling experiments show that crystal volume and size increase as cooling rate decreases. Anosovite and gangue mineral crystals develop fully with large crystal volume and size at a cooling rate of 2 K.min-1. Moreover, the growth of anosovite crystal was characterized by crystal nucleation and growth theory. These results provide further insights into the separation of anosovite from gangue by mineral processing.