Metal-organic framework-derived Co-C catalyst for the selective hydrogenation of cinnamaldehyde to cinnamic alcohol

The liquid phase selective hydrogenation of cinnamaldehyde has been investigated over the catalysts Co-C-T(T=400-700℃),which were derived from the carbonization of the MOF precursor Co-BTC at different temperatures in inert atmosphere.Co-C-500 exhibited a higher conversion(85.3%)than those carbonized at other temperatures,with 51.5%selectivity to cinnamyl alcohol,under a mild condition(90℃,4 h,2 MPa H_(2),solvent:9 ml ethanol and 1 ml water).The high catalytic activity of Co-C-500 can be ascribed to the large specific surface area of the catalyst,the uniformly dispersed metallic cobalt nanoparticles,and the more defect sites on the carbon support.Moreover,Co-C-500 showed excellent reusability in 5 successive cycles,mainly related to the uniformly dispersed cobalt nanoparticles embedded in carbon support.

Removal of Cr(VI)from aqueous solution by Rice-husk-based activated carbon prepared by Dual-mode heating method

Rice husk-based activated carbon was prepared with the help of zinc chloride using microwave and electrical dual-mode heating.The pore characteristics and chemical properties of rice husk-based activated carbon(RH-AC)were characterized by BET,XRD,Raman spectra,FTIR and pHIEP(pH of isoelectric point).The specific surface area of RH-AC is 1719.32 m^(2)/g with a total pore volume of 1.05 cm^(3)/g.The performance of RH-AC for removing Cr(VI)from aqueous solution was examined considering the variation of the contact time(0-120 min),pH value(2.0-9.0),adsorbent dose(0.5-3.0 g/L),initial concentration(28-145 mg/L)and solvent temperature(15-45℃).The ideal pH for Cr(VI)removal is between 2.0 and 3.0 with the equilibrium time of 90 min,achieving the maximum adsorption capacity of 56.82 mg/g with the pH of 3.0.Comparable study on the established kinetic models and isotherms to simulate the removal of Cr(VI)by RH-AC was carried out to sort out the inherent mechanism of the absorption.Reasonable agreements could be obtained by the pseudo-second-order kinetic model and Langmuir,Freundlich and Tempkin isothermal models.Results from Body model simulation suggest that external mass transfer was the essential cause for rate-controlling in the adsorption process of Cr(VI).