A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H ...A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H 3PW 12 O 40 /SiO 2 was characterized by IR,XRD and TEM.The following optimum condition were that the mole ratio of alcohol to carboxylic acid is 27∶1,the temperature is 75℃,the reaction time is 5 hours,and the catalyst is 2 5% of feedstock.Under the optimum conditions,the yield of esters was above 94%.展开更多
12‐Tungstophosphoric acid supported on aerosil silica and silica‐coated γ‐Fe2O3 nanoparticles was prepared and characterized using transmission electron microscopy,scanning electron microscopy,and inductively coup...12‐Tungstophosphoric acid supported on aerosil silica and silica‐coated γ‐Fe2O3 nanoparticles was prepared and characterized using transmission electron microscopy,scanning electron microscopy,and inductively coupled plasma atomic emission spectroscopy.The catalytic activity of the two prepared catalysts was compared in the synthesis of 1,8‐dioxo‐9,10‐diaryldecahydroacridines in water.12‐Tungstophosphoric acid was highly dispersed on the silica‐coated γ‐Fe2O3 nanoparticles and showed higher activity and a higher reuse number compared with the acid supported on aerosil silica.The catalyst could be recovered simply by using an external magnetic field and could be reused several times without appreciable loss of its catalytic activity.展开更多
The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were ...The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were studied. The results showed that the doping of Fe 3+ , Co 2+ , Ni 2+ and Cr 3+ in TiO 2 nanoparticles made the photocatalytic efficiency of the TiO 2 particles reduce and the higher the initial content of Fe 3+ , the lower the ability of TiO 2 in photocatalyzing the degradation of RB. But the doping of Zn 2+ and Cd 2+ , especially Zn 2+ , made the photocatalytic efficiency of the TiO 2 particles enhance, showing a great increase of the rate constant( k ) and the initial reaction rate( r ini ).展开更多
文摘A nanosolid heteropoly acid of H 3PW 12 O 40 /SiO 2 was prepared with the sol-gel method and used to catalyze sythesis of methyl 5-amino-1,2,4,-trazolylformate sulfate.The structure of the nanosolid heteropoly acid H 3PW 12 O 40 /SiO 2 was characterized by IR,XRD and TEM.The following optimum condition were that the mole ratio of alcohol to carboxylic acid is 27∶1,the temperature is 75℃,the reaction time is 5 hours,and the catalyst is 2 5% of feedstock.Under the optimum conditions,the yield of esters was above 94%.
基金supported by Razi University Research Council and Iran National Science Foundation
文摘12‐Tungstophosphoric acid supported on aerosil silica and silica‐coated γ‐Fe2O3 nanoparticles was prepared and characterized using transmission electron microscopy,scanning electron microscopy,and inductively coupled plasma atomic emission spectroscopy.The catalytic activity of the two prepared catalysts was compared in the synthesis of 1,8‐dioxo‐9,10‐diaryldecahydroacridines in water.12‐Tungstophosphoric acid was highly dispersed on the silica‐coated γ‐Fe2O3 nanoparticles and showed higher activity and a higher reuse number compared with the acid supported on aerosil silica.The catalyst could be recovered simply by using an external magnetic field and could be reused several times without appreciable loss of its catalytic activity.
文摘The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were studied. The results showed that the doping of Fe 3+ , Co 2+ , Ni 2+ and Cr 3+ in TiO 2 nanoparticles made the photocatalytic efficiency of the TiO 2 particles reduce and the higher the initial content of Fe 3+ , the lower the ability of TiO 2 in photocatalyzing the degradation of RB. But the doping of Zn 2+ and Cd 2+ , especially Zn 2+ , made the photocatalytic efficiency of the TiO 2 particles enhance, showing a great increase of the rate constant( k ) and the initial reaction rate( r ini ).
