Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method.Bimetallic catalysts LaPt/SAPO-11 or CePt/SAPO-11 was prepared by sequential impregnation method.The catalysts were characterized by X-ray diffracti...Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method.Bimetallic catalysts LaPt/SAPO-11 or CePt/SAPO-11 was prepared by sequential impregnation method.The catalysts were characterized by X-ray diffraction(XRD),nitrogen adsorption,temperature-programmed desorption of ammonia(NH3-TPD),and Fourier transform infrared spectroscopy(FT-IR) techniques.The results showed that with the addition of rare earths the BET surface areas,pore volume,the amount of Bronsted acid and the total acidity of catalys...展开更多
The Ni/SAPO-11 catalyst used for n-hexane hydroisomerization was prepared via a novel two-step crystallization strategy.It involves introduction of nickel salt into the pre-crystalized system of SAPO-11 by grinding fo...The Ni/SAPO-11 catalyst used for n-hexane hydroisomerization was prepared via a novel two-step crystallization strategy.It involves introduction of nickel salt into the pre-crystalized system of SAPO-11 by grinding followed by a second crystallization step.No extra solvent is introduced during the whole synthesis procedure which reduces waste liquid emissions significantly.More importantly,interaction between nickel and support is effectively regulated by the novel method to achieve a well dispersed nickel species and inhibit formation of inert nickel spinel simultaneously.Chemical environments of framework Si are tuned to enhance surface acidity of the Ni/SAPO-11 catalyst.It also shows smaller particle size which favors fast diffusion of reactants and products.Insights into the two-step crystallization indicate that accumulation of SAPO-11 precursors in the pre-crystallization stage,pH regulation by nickel salt and structural directing effect of Ni2+during the second crystallization period account for the rapid crystal growth and smaller particle size of the Ni/SAPO-11 catalyst.All the unique features endow the Ni/SAPO-11 catalyst higher activity and isomers selectivity than the Pt/SAPO-11 catalyst in n-hexane hydroisomerization.展开更多
For enhancing the activity of Ni/TiO2-SAPO-11 catalyst, SAPO-11, the precursor was prepared by hydrothermal crystallization, and TiO2-SAPO-11 complex carrier was prepared by sol-gel method, then Ni/TiO2-SAPO-11 was pr...For enhancing the activity of Ni/TiO2-SAPO-11 catalyst, SAPO-11, the precursor was prepared by hydrothermal crystallization, and TiO2-SAPO-11 complex carrier was prepared by sol-gel method, then Ni/TiO2-SAPO-11 was produced by the final product. The catalytic performance of Ni/TiO2-SAPO-11 was studied in n-heptane isomerization, and the impact of catalyst preparation conditions on n-heptane isomerization was discussed in detail. The results showed that, with 20% of TiO2 composition, 2% of Ni capacity percentage and calcined temperature at 500°C, conversion of n-heptane and isomerization selectivity was up to 40.94% and 88.97% respectively.展开更多
Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,s...Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption,pyridine-adsorbed infrared spectroscopy,temperature-programmed desorption of NH3,temperature-programmed reduction of hydrogen,temperature-programmed desorption of hydrogen,transmission electron microscopy,and X-ray photoelectron spectroscopy.The addition of zinc resulted in high dispersion of platinum.Zinc acted as a competitive adsorbent,changed the location of platinum.The catalyst with a zinc loading of 0.5%gave the highest selectivity to dimethylhexanes,but the conversion was lower than those achieved with the other catalysts.Dimethylhexanes have large molecular diameters,and therefore their diffusion may be difficult.This weakens the catalytic activity of the zinc-modified catalysts and lowers the n-octane conversion.展开更多
In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the seri...In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the series of hexaaluminates had almost the same magnetoplumbite crystal structure, however, they exhibted different reducibility and catalytic activities for CO 2 reforming of methane to synthesis gas. Among the LaMAl 11 O 19-δ samples, LaNiAl 11 O 19-δ showed the best catalytic activity for the reaction at 1 053 K for 2 h, the conversion of CH 4 and CO 2 was 98.8% and 97.6%, respectively, and the catalytic activities of rest Msubstituted catalysts were extremely lower than that of LaNiAl 11 O 19-δ . The sequence of affection on catalytic activity of transition metal M for the topic reaction was NiCo>Fe> Mn> Cu.展开更多
A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sinte...A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sintering at high reaction temperature. Ascompared with La2O3-Ni/SrAl12O19, in the CH4+CO2 reaction, LaNiAl11O19 catalyst displaysa higher catalytic activity, lower coking amount and excellent sintering resistance of Niparticle, due to its stable structure.展开更多
基金supported by the Foundation of Jiangsu Key Laboratory of Precious Metals Chemistry (SYGK0710)Natural Scientific Foundation of Jiangsu Teachers University of Technology (KYY06029)
文摘Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method.Bimetallic catalysts LaPt/SAPO-11 or CePt/SAPO-11 was prepared by sequential impregnation method.The catalysts were characterized by X-ray diffraction(XRD),nitrogen adsorption,temperature-programmed desorption of ammonia(NH3-TPD),and Fourier transform infrared spectroscopy(FT-IR) techniques.The results showed that with the addition of rare earths the BET surface areas,pore volume,the amount of Bronsted acid and the total acidity of catalys...
基金supported by the National Natural Science Foundation of China(22108308,21978326,21991091)the Natural Science Foundation of Shandong Province(ZR2021QB062,ZR2019MB029)+2 种基金the China Postdoctoral Science Foundation(2020M682259)the Project of Qingdao West Coast New Area District Science and Technology Innovation Center(Grant No.20202-2)the Fundamental Research Funds for the Central Universities(22CX06014A)。
文摘The Ni/SAPO-11 catalyst used for n-hexane hydroisomerization was prepared via a novel two-step crystallization strategy.It involves introduction of nickel salt into the pre-crystalized system of SAPO-11 by grinding followed by a second crystallization step.No extra solvent is introduced during the whole synthesis procedure which reduces waste liquid emissions significantly.More importantly,interaction between nickel and support is effectively regulated by the novel method to achieve a well dispersed nickel species and inhibit formation of inert nickel spinel simultaneously.Chemical environments of framework Si are tuned to enhance surface acidity of the Ni/SAPO-11 catalyst.It also shows smaller particle size which favors fast diffusion of reactants and products.Insights into the two-step crystallization indicate that accumulation of SAPO-11 precursors in the pre-crystallization stage,pH regulation by nickel salt and structural directing effect of Ni2+during the second crystallization period account for the rapid crystal growth and smaller particle size of the Ni/SAPO-11 catalyst.All the unique features endow the Ni/SAPO-11 catalyst higher activity and isomers selectivity than the Pt/SAPO-11 catalyst in n-hexane hydroisomerization.
文摘For enhancing the activity of Ni/TiO2-SAPO-11 catalyst, SAPO-11, the precursor was prepared by hydrothermal crystallization, and TiO2-SAPO-11 complex carrier was prepared by sol-gel method, then Ni/TiO2-SAPO-11 was produced by the final product. The catalytic performance of Ni/TiO2-SAPO-11 was studied in n-heptane isomerization, and the impact of catalyst preparation conditions on n-heptane isomerization was discussed in detail. The results showed that, with 20% of TiO2 composition, 2% of Ni capacity percentage and calcined temperature at 500°C, conversion of n-heptane and isomerization selectivity was up to 40.94% and 88.97% respectively.
基金supported by the National Natural Science Foundation of China(21676300)~~
文摘Zinc-modified Pt/SAPO-11 catalysts were prepared by incipient wetness impregnation and assessed in the hydroisomerization of n-octane.Their physicochemical properties were investigated using powder X-ray diffraction,scanning electron microscopy,nitrogen adsorption-desorption,pyridine-adsorbed infrared spectroscopy,temperature-programmed desorption of NH3,temperature-programmed reduction of hydrogen,temperature-programmed desorption of hydrogen,transmission electron microscopy,and X-ray photoelectron spectroscopy.The addition of zinc resulted in high dispersion of platinum.Zinc acted as a competitive adsorbent,changed the location of platinum.The catalyst with a zinc loading of 0.5%gave the highest selectivity to dimethylhexanes,but the conversion was lower than those achieved with the other catalysts.Dimethylhexanes have large molecular diameters,and therefore their diffusion may be difficult.This weakens the catalytic activity of the zinc-modified catalysts and lowers the n-octane conversion.
文摘In this paper, a series of hexaaluminate oxides, LaMAl 11 O 19-δ (M=Fe, Co, Ni, Mn and Cu), were prepared using transition metals M to substitute Al in the hexaaluminate lattices. XRD analyses indicated that the series of hexaaluminates had almost the same magnetoplumbite crystal structure, however, they exhibted different reducibility and catalytic activities for CO 2 reforming of methane to synthesis gas. Among the LaMAl 11 O 19-δ samples, LaNiAl 11 O 19-δ showed the best catalytic activity for the reaction at 1 053 K for 2 h, the conversion of CH 4 and CO 2 was 98.8% and 97.6%, respectively, and the catalytic activities of rest Msubstituted catalysts were extremely lower than that of LaNiAl 11 O 19-δ . The sequence of affection on catalytic activity of transition metal M for the topic reaction was NiCo>Fe> Mn> Cu.
文摘A new type of the catalyst, LaNiAl11O19 for the methane reforming with carbondioxide was synthesized and evaluated. LaNiAl11O19 has a hexaaluminate structure and cankeep large surface and heat resistance against sintering at high reaction temperature. Ascompared with La2O3-Ni/SrAl12O19, in the CH4+CO2 reaction, LaNiAl11O19 catalyst displaysa higher catalytic activity, lower coking amount and excellent sintering resistance of Niparticle, due to its stable structure.
