La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and t...La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.展开更多
The metallic states of ultrafine amorphous alloy particles CoB, CoPB and Co metal were studied by using JCP, XPS and ethylene hydrogenation reaction test. It is shown that Co component on surface of CoB and CoPB amorp...The metallic states of ultrafine amorphous alloy particles CoB, CoPB and Co metal were studied by using JCP, XPS and ethylene hydrogenation reaction test. It is shown that Co component on surface of CoB and CoPB amorphous alloy particles is in electron-deficient state, which leads to the increase of irreversible absorption of ethylene,and results in the decrease of the active site number. Hence the catalytic activity of CoB and CoPB catalysts for ethylenc hydrogenation is lower than that of metallic Co.展开更多
Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and struct...Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and structure of the ultrafine particle catalyst has been studied by using TEM, DTA-TG, FT-IR, XRD and BET surface area measurement methods. It is shown that the BET surface area of Fe2(MoO4)3 ultrafine particle prepared by sol-gel method is much larger than that of Fe2(MoO4)3 prepared by coprecipitation method. For the preparation of the welldistribuated Fe2(MoO4)3 ultrafine particles with the size in the range of 40-80nm, the optimumconditions are : treatment temperature <673K, L/M (Citric acid/Metallic ions)=0.3 and pH<1 .0.展开更多
文摘La-Mo series complex oxide ultrafine particles have been prepared successfully by the sol-gel method at low tomperature. The infiuence of preparation conditions and thermal treatment conditions on the morphology and the structure of the oxide particles has been studied by using XRD, DTA-TG, TEM, FT-IR and BET surface area measurement methods. For the preparation of the well-distributed La-Mo series complex oxide ultrafine particles with the size in the range of 40-80nm, the optimum conditions are:ncitrie/nLa+Mo=0.3, pH≤1.5, t≤500℃.
文摘The metallic states of ultrafine amorphous alloy particles CoB, CoPB and Co metal were studied by using JCP, XPS and ethylene hydrogenation reaction test. It is shown that Co component on surface of CoB and CoPB amorphous alloy particles is in electron-deficient state, which leads to the increase of irreversible absorption of ethylene,and results in the decrease of the active site number. Hence the catalytic activity of CoB and CoPB catalysts for ethylenc hydrogenation is lower than that of metallic Co.
文摘Fe2(MoO4)3 ultrafine particle catalyst has been prepared successfully by the sol-gel process at lower temperature. The influences of preparation conditions and thermal treatment conditions on the morphology and structure of the ultrafine particle catalyst has been studied by using TEM, DTA-TG, FT-IR, XRD and BET surface area measurement methods. It is shown that the BET surface area of Fe2(MoO4)3 ultrafine particle prepared by sol-gel method is much larger than that of Fe2(MoO4)3 prepared by coprecipitation method. For the preparation of the welldistribuated Fe2(MoO4)3 ultrafine particles with the size in the range of 40-80nm, the optimumconditions are : treatment temperature <673K, L/M (Citric acid/Metallic ions)=0.3 and pH<1 .0.
