Ferrierite(FER) zeolites were synthesized by solid transformation at different alkalinities(OH-/Al2O3 molar ratios). The in situ delamination of FER zeolites were achieved and their catalytic performances in the catal...Ferrierite(FER) zeolites were synthesized by solid transformation at different alkalinities(OH-/Al2O3 molar ratios). The in situ delamination of FER zeolites were achieved and their catalytic performances in the catalytic cracking of C4 hydrocarbons were examined. The relationships among the OH-/Al2O3 molar ratio, FER structure,composition, surface acidity and catalytic performance in C4 hydrocarbon cracking were investigated. The results of X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, N2 adsorption, NH3temperature-programmed desorption and catalytic cracking showed that with increasing OH-/Al2O3 molar ratio in the synthesis gel, the Si O2/Al2O3 molar ratio of the as-synthesized FER zeolite decreased, the amount of acid sites in the corresponding H-FER increased, and the acid strength weakened. Additionally, the FER zeolite was delaminated at the mesoscale. H-FER5 synthesized at the highest alkalinity had the largest number of acid sites and exhibited the highest catalytic activity in C4 hydrocarbon catalytic cracking among three of the prepared catalysts. H-FER3 synthesized at the secondhighest alkalinity showed that the highest yield of benzene and toluene because of the secondary pores resulted from the gaps between the layers, which were beneficial to the diffusion and formation of large molecules.展开更多
The catalytic conversion of methanol to dimethyl ether(DME) over a series of home-made FER-type zeolites having different acidities and commercial γ-Al_2O_3 has been studied with the aim to understand the impact of a...The catalytic conversion of methanol to dimethyl ether(DME) over a series of home-made FER-type zeolites having different acidities and commercial γ-Al_2O_3 has been studied with the aim to understand the impact of adding water in the reactant stream on the catalytic behavior on investigated materials. Cofeeding water with methanol, the alcohol conversion was slightly reduced over the investigated zeolites while the catalytic activity of γ-Al_2O_3, the traditional catalyst of MeOH-to-DME conversion, was strongly inhibited. It was also found that, for the investigated zeolites, both the amount and the initial deposition rate of the coke formed during the reaction were reduced when water was co-fed with methanol while no significant effects on both methanol conversion and DME selectivity were observed under the investigated conditions.展开更多
Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous a-alumina support. These membranes were characterized by means of X...Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous a-alumina support. These membranes were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and pervaporation tests.展开更多
This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the applicatio...This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the application of adsorption processes in removal of light hydrocarbons from exhaust streams of the petrochemical industry and of light-duty gasoline vehicles under cold start conditions (C4-C5 paraffins and olefins). The materials investigated were 5A and Ferrierite zeolites, characterized by different pore opening and Si/Al ratio. Equilibrium isotherm curves at room temperature were determined by a gravimetric method on dehydrated zeolites, while breakthrough curves in dynamic tests were used to evaluate the adsorption properties of hydrated zeolites at low hydrocarbon partial pressure (0-1 kPa) and in experimental conditions close to those of a HC trap at the engine exhaust. The experimental results regarding the adsorption capacities were discussed with the aim to understand how the physico-chemical characteristics of the adsorbent material could affect its trapping capability in adsorbing different types of hydrocarbons.展开更多
The hydrothermal crystallization of THF-FER zeolite was investigated in the reactant system of Na2O-SiO2-Al2O3-H2O with tetrahydrofuran (THF) as the template in the presence of various catalytic amount of glycerol [...The hydrothermal crystallization of THF-FER zeolite was investigated in the reactant system of Na2O-SiO2-Al2O3-H2O with tetrahydrofuran (THF) as the template in the presence of various catalytic amount of glycerol [CH2(OH)CH(OH)CH2(OH), Glyc] in the temperature range of 413--473 K. Powder X-ray diffraction (XRD) was used to observe the crystallization process, and scanning electron microscope (SEM), ^13C cross polarization (CP) and ^27Al magic angle spinning nuclear magnetic resonance (MAS NMR), X-ray fluorescence scattering spectroscopy (XRF), thermal analysis and nitrogen sorption were used to characterize the zeolite synthesized in the reactant system with Glyc. The catalytic amount of Glyc could promote the crystallization of FER zeolite, to result in lowering the reaction temperature, shortening the period of the zeolite crystallization and effectively restraining cocrystallization of MOR zeolite as an impure phase especially at low reaction temperature, and possess a significant effect on the morphology and the crystal size of TI-IF-FER zeolite.展开更多
基金Supported by the NSFC of China(20973123)the National Basic Research Program of China(2012CB215002)+1 种基金the International Science and Technology Cooperative Program of China(2010DFB40440)Shanxi Basic Research Projects(2012011005-7,2012011008-3)
文摘Ferrierite(FER) zeolites were synthesized by solid transformation at different alkalinities(OH-/Al2O3 molar ratios). The in situ delamination of FER zeolites were achieved and their catalytic performances in the catalytic cracking of C4 hydrocarbons were examined. The relationships among the OH-/Al2O3 molar ratio, FER structure,composition, surface acidity and catalytic performance in C4 hydrocarbon cracking were investigated. The results of X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy, N2 adsorption, NH3temperature-programmed desorption and catalytic cracking showed that with increasing OH-/Al2O3 molar ratio in the synthesis gel, the Si O2/Al2O3 molar ratio of the as-synthesized FER zeolite decreased, the amount of acid sites in the corresponding H-FER increased, and the acid strength weakened. Additionally, the FER zeolite was delaminated at the mesoscale. H-FER5 synthesized at the highest alkalinity had the largest number of acid sites and exhibited the highest catalytic activity in C4 hydrocarbon catalytic cracking among three of the prepared catalysts. H-FER3 synthesized at the secondhighest alkalinity showed that the highest yield of benzene and toluene because of the secondary pores resulted from the gaps between the layers, which were beneficial to the diffusion and formation of large molecules.
文摘The catalytic conversion of methanol to dimethyl ether(DME) over a series of home-made FER-type zeolites having different acidities and commercial γ-Al_2O_3 has been studied with the aim to understand the impact of adding water in the reactant stream on the catalytic behavior on investigated materials. Cofeeding water with methanol, the alcohol conversion was slightly reduced over the investigated zeolites while the catalytic activity of γ-Al_2O_3, the traditional catalyst of MeOH-to-DME conversion, was strongly inhibited. It was also found that, for the investigated zeolites, both the amount and the initial deposition rate of the coke formed during the reaction were reduced when water was co-fed with methanol while no significant effects on both methanol conversion and DME selectivity were observed under the investigated conditions.
文摘Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous a-alumina support. These membranes were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and pervaporation tests.
文摘This paper reports the results of an experimental study on adsorption of light hydrocarbons on small pore microporous materials. The choice of hydrocarbons studied was affected taking into consideration the application of adsorption processes in removal of light hydrocarbons from exhaust streams of the petrochemical industry and of light-duty gasoline vehicles under cold start conditions (C4-C5 paraffins and olefins). The materials investigated were 5A and Ferrierite zeolites, characterized by different pore opening and Si/Al ratio. Equilibrium isotherm curves at room temperature were determined by a gravimetric method on dehydrated zeolites, while breakthrough curves in dynamic tests were used to evaluate the adsorption properties of hydrated zeolites at low hydrocarbon partial pressure (0-1 kPa) and in experimental conditions close to those of a HC trap at the engine exhaust. The experimental results regarding the adsorption capacities were discussed with the aim to understand how the physico-chemical characteristics of the adsorbent material could affect its trapping capability in adsorbing different types of hydrocarbons.
文摘The hydrothermal crystallization of THF-FER zeolite was investigated in the reactant system of Na2O-SiO2-Al2O3-H2O with tetrahydrofuran (THF) as the template in the presence of various catalytic amount of glycerol [CH2(OH)CH(OH)CH2(OH), Glyc] in the temperature range of 413--473 K. Powder X-ray diffraction (XRD) was used to observe the crystallization process, and scanning electron microscope (SEM), ^13C cross polarization (CP) and ^27Al magic angle spinning nuclear magnetic resonance (MAS NMR), X-ray fluorescence scattering spectroscopy (XRF), thermal analysis and nitrogen sorption were used to characterize the zeolite synthesized in the reactant system with Glyc. The catalytic amount of Glyc could promote the crystallization of FER zeolite, to result in lowering the reaction temperature, shortening the period of the zeolite crystallization and effectively restraining cocrystallization of MOR zeolite as an impure phase especially at low reaction temperature, and possess a significant effect on the morphology and the crystal size of TI-IF-FER zeolite.