NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase io...NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase ion exchange between NaY zeolite and cerium nitrate. The performance of two Y zeolites [Ce(IV)Y(1) and Ce(IV)Y(2)] was compared through static selective adsorptive desulfurization of FCC gasoline at room temperature and normal pressure. The sulfur compounds and contents of the FCC gasoline were analyzed by microcoulometry and GC-SCD chromatogram. The results showed that the effect of adsorptive desulfurization of FCC gasoline achieved by Ce(IV)Y(1) zeolite was better than that of Ce(IV)Y(2) zeolite. The rate for adsorptive desulfurization of FCC gasoline by Ce(IV)Y(1) zeolite and Ce(IV)Y(2) zeolite was 85.0% and 62.4%, respectively. The Ce(IV)Y(1) zeolite could adsorb DMTs, which could not be adsorbed by Ce(IV)Y(2) zeolite. The rate of regeneration of extruded Ce(IV)Y(1)zeolite was 95.5%.展开更多
NH4Y zeolite was prepared through ion-exchange of NaY zeolite with an ammonium salt. Then LaY zeolite was obtained through a secondary ion-exchange of NHaY zeolite with a rare earth salt solution followed by calcinati...NH4Y zeolite was prepared through ion-exchange of NaY zeolite with an ammonium salt. Then LaY zeolite was obtained through a secondary ion-exchange of NHaY zeolite with a rare earth salt solution followed by calcination of the zeolite product. Dynamic adsorptive desulfurization of naphtha was conducted in the presence of the modified LaY zeolite, and the sulfur content of the treated naphtha samples was analyzed by microcoulometry. The test results showed that under dynamic conditions the LaY zeolite prepared through secondary ion-exchange of NH4Y zeolite, which was prepared using 1.0 mol/L ammonium salt, with the rare earth salt exhibited a better desulfurization efficiency. Furthermore, the LaY zeolite achieved a best desulfurization effect at an adsorption temperature of 45 ℃ and an adsorbent/oil ratio of 1：2.展开更多
We have investigated creation of variable concentrations of defects on TIO2（110）-（1×1） surface by 266 nm laser using temperature programmed desorption technique. Oxygen-vacancy defects can be easily induced b...We have investigated creation of variable concentrations of defects on TIO2（110）-（1×1） surface by 266 nm laser using temperature programmed desorption technique. Oxygen-vacancy defects can be easily induced by ultraviolet light, the defects concentration has a linear dependence on power density higher than 50 mW/cm2 for 90 s irradiation. No observation of O2 molecule and Ti atom desorption suggests that UV induced defects creation on TiO2（110）-（1×1） is an effective and gentle method. With pre-dosage of thin films of water, the rate of defects creation on TiO2（110）-（1×1） is slower at least by two orders of magnitude than bare TiO2（110）-（1×1） surface. Further investigations show that water can be more easily desorbed by UV light, and thus desorption of bridging oxygen is depressed.展开更多
基金the National Natural Sci-ence Foundation of China (No.20476042 and No.20776064) for the financial support.
文摘NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase ion exchange between NaY zeolite and cerium nitrate. The performance of two Y zeolites [Ce(IV)Y(1) and Ce(IV)Y(2)] was compared through static selective adsorptive desulfurization of FCC gasoline at room temperature and normal pressure. The sulfur compounds and contents of the FCC gasoline were analyzed by microcoulometry and GC-SCD chromatogram. The results showed that the effect of adsorptive desulfurization of FCC gasoline achieved by Ce(IV)Y(1) zeolite was better than that of Ce(IV)Y(2) zeolite. The rate for adsorptive desulfurization of FCC gasoline by Ce(IV)Y(1) zeolite and Ce(IV)Y(2) zeolite was 85.0% and 62.4%, respectively. The Ce(IV)Y(1) zeolite could adsorb DMTs, which could not be adsorbed by Ce(IV)Y(2) zeolite. The rate of regeneration of extruded Ce(IV)Y(1)zeolite was 95.5%.
文摘NH4Y zeolite was prepared through ion-exchange of NaY zeolite with an ammonium salt. Then LaY zeolite was obtained through a secondary ion-exchange of NHaY zeolite with a rare earth salt solution followed by calcination of the zeolite product. Dynamic adsorptive desulfurization of naphtha was conducted in the presence of the modified LaY zeolite, and the sulfur content of the treated naphtha samples was analyzed by microcoulometry. The test results showed that under dynamic conditions the LaY zeolite prepared through secondary ion-exchange of NH4Y zeolite, which was prepared using 1.0 mol/L ammonium salt, with the rare earth salt exhibited a better desulfurization efficiency. Furthermore, the LaY zeolite achieved a best desulfurization effect at an adsorption temperature of 45 ℃ and an adsorbent/oil ratio of 1：2.
文摘We have investigated creation of variable concentrations of defects on TIO2（110）-（1×1） surface by 266 nm laser using temperature programmed desorption technique. Oxygen-vacancy defects can be easily induced by ultraviolet light, the defects concentration has a linear dependence on power density higher than 50 mW/cm2 for 90 s irradiation. No observation of O2 molecule and Ti atom desorption suggests that UV induced defects creation on TiO2（110）-（1×1） is an effective and gentle method. With pre-dosage of thin films of water, the rate of defects creation on TiO2（110）-（1×1） is slower at least by two orders of magnitude than bare TiO2（110）-（1×1） surface. Further investigations show that water can be more easily desorbed by UV light, and thus desorption of bridging oxygen is depressed.
