以液相离子交换法制备了一系列不同Cu负载量的Cu Na Y分子筛;采用XRD及N2吸附-脱附表征分子筛的微观结构和织构性质,采用动态吸附法考察其对噻吩模拟油的吸附脱硫性能,结合NH_3-TPD和Py-FTIR方法对CuNaY分子筛的酸量和有效Cu^+物种进行...以液相离子交换法制备了一系列不同Cu负载量的Cu Na Y分子筛;采用XRD及N2吸附-脱附表征分子筛的微观结构和织构性质,采用动态吸附法考察其对噻吩模拟油的吸附脱硫性能,结合NH_3-TPD和Py-FTIR方法对CuNaY分子筛的酸量和有效Cu^+物种进行定量分析,研究了CuNaY分子筛的表面酸性和铜物种形态结构对其吸附脱硫性能的影响机制。结果表明,通过改变铜负载量可有效调控改性Y分子筛的表面酸性以及铜物种化学形态;适量铜物种的引入可以最大限度的形成有效吸附位,从而获得最优吸附脱硫性能,而过量的Cu物种会在Y分子筛笼内形成多核铜物种结构,导致有效吸附位点的减少,影响其对噻吩的吸附能力。展开更多
The heterogeneity of adsorption sites and adsorption kinetics of n-hexane on a chromium terephthalate-based metal–organic framework MIL-101(Cr) were studied by gravimetric method and temperature-programmed desorption...The heterogeneity of adsorption sites and adsorption kinetics of n-hexane on a chromium terephthalate-based metal–organic framework MIL-101(Cr) were studied by gravimetric method and temperature-programmed desorption(TPD) experiments. The MIL-101 crystals were synthesized by microwave irradiation method. The adsorption isotherms and kinetic curves of n-hexane on the MIL-101 were measured. Desorption activation energies of n-hexane from the MIL-101 were estimated by TPD experiments. The results showed that equilibrium amount of n-hexane adsorbed on the MIL-101 was up to 5.62 mmol·g-1at 298 K and 1.6 × 104 Pa, much higher than that of some activated carbons, zeolites and so on. The isotherms of n-hexane on the MIL-101 could be well fitted with Langmuir–Freundlich model. TPD spectra exhibit two types of adsorption sites on the MIL-101 with desorption activation energies of 39.41 and 86.69 kJ·mol-1. It reflects the surface energy heterogeneity on the MIL-101 frameworks for n-hexane adsorption. The diffusion coefficients of n-hexane are in the range of(1.35–2.35) × 10-10cm2·s-1with adsorption activation energy of 16.33 kJ·mol^(-1).展开更多
文摘以液相离子交换法制备了一系列不同Cu负载量的Cu Na Y分子筛;采用XRD及N2吸附-脱附表征分子筛的微观结构和织构性质,采用动态吸附法考察其对噻吩模拟油的吸附脱硫性能,结合NH_3-TPD和Py-FTIR方法对CuNaY分子筛的酸量和有效Cu^+物种进行定量分析,研究了CuNaY分子筛的表面酸性和铜物种形态结构对其吸附脱硫性能的影响机制。结果表明,通过改变铜负载量可有效调控改性Y分子筛的表面酸性以及铜物种化学形态;适量铜物种的引入可以最大限度的形成有效吸附位,从而获得最优吸附脱硫性能,而过量的Cu物种会在Y分子筛笼内形成多核铜物种结构,导致有效吸附位点的减少,影响其对噻吩的吸附能力。
基金Supported by the National Natural Science Foundation of China(21276092)the Research Foundation of State Key Lab of Subtropical Building Science of China(C713001z)+2 种基金the Science and Technology Research Foundation of Guangzhou City,China(200910814001)Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control(2011A060901011)the Fundamental Research Funds for the Central Universities(2013ZZ0060 and 2013ZM0056)
文摘The heterogeneity of adsorption sites and adsorption kinetics of n-hexane on a chromium terephthalate-based metal–organic framework MIL-101(Cr) were studied by gravimetric method and temperature-programmed desorption(TPD) experiments. The MIL-101 crystals were synthesized by microwave irradiation method. The adsorption isotherms and kinetic curves of n-hexane on the MIL-101 were measured. Desorption activation energies of n-hexane from the MIL-101 were estimated by TPD experiments. The results showed that equilibrium amount of n-hexane adsorbed on the MIL-101 was up to 5.62 mmol·g-1at 298 K and 1.6 × 104 Pa, much higher than that of some activated carbons, zeolites and so on. The isotherms of n-hexane on the MIL-101 could be well fitted with Langmuir–Freundlich model. TPD spectra exhibit two types of adsorption sites on the MIL-101 with desorption activation energies of 39.41 and 86.69 kJ·mol-1. It reflects the surface energy heterogeneity on the MIL-101 frameworks for n-hexane adsorption. The diffusion coefficients of n-hexane are in the range of(1.35–2.35) × 10-10cm2·s-1with adsorption activation energy of 16.33 kJ·mol^(-1).
