The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobe...The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobenzene\}( p -CNB) was studied. The results indicate that the activity of Ru-Pt/ γ -Al 2O 3[\{ n (ruthenium)\}∶ n (platinum)=4∶1] is much higher than that of Ru/ γ -Al 2O 3,while the amount of dehalogenation product(aniline) and other by-products are much fewer than that by using Pt/ γ -Al 2O 3 as the catalyst. There is synergistic effect of ruthenium and platinum in bimetallic catalyst for selective hydrogenation of p -CNB. Under the reaction conditions t =50 ℃, p H 2 = 1.0 MPa, reaction time 60 min,\{ n (substrate)∶\} n (total amount of metal content)=1000∶1,the conversion of p -CNB and the selectivity to p -chloroaniline( p -CNA) by using Ru-Pt/ γ -Al 2O 3 as the catalyst are 48.2% and 85.9%,respectively. The effect of other metal cations(introduced to the reaction system with the corresponding metal chloride solution) on the reaction was investigated. It was found that catalytic performance of Ru-Pt/ γ -Al 2O 3 could be greatly improved by modfication of some metal cations. When Co 2+ and Ni 2+ were used as modifiers for the catalyst Ru-Pt/ γ -Al 2O 3 under above mentioned reaction conditions,the conversions of p -CNB increase to 74.5% and 87.8%,as well as the selectivities of p -CAN increase to 98.9% and 99.4%,respectively. Fe 3+ and Sn 4+ were the best modifiers for Ru-Pt/ γ -Al 2O 3 under the same reaction conditions. The conversions of p -CNB and the selectivities of p -CAN can reach 100% and >99.0%,respectively. However,the catalysts can be poisoned by Zn 2+ and Sn 2+ .展开更多
Using Zn（SO4）2·7H2O and H2C2O4·2H2O as raw materials,nanometer ZnO was prepared by liquid-phase precipitation method,the synthetic process and the properties of the product were studied by XRD,TG-DTA,TEM a...Using Zn（SO4）2·7H2O and H2C2O4·2H2O as raw materials,nanometer ZnO was prepared by liquid-phase precipitation method,the synthetic process and the properties of the product were studied by XRD,TG-DTA,TEM and IR.Ultrasonic washing with 0.05 mol·L-1 H2C2O4 solution,vacuum dry to ZnC2O4·2H2O precusor can improve the powder properties notably.The product ZnO crystalline has hexagonal strcture and an anaverage diameter of 23 nm with good dispersity and spherical shape.展开更多
Three new Dawson-type HPCs:K14·24H2O,K15H3·26H2O and K15H3·27H2O were synthesized for the first time.They are tungstophosphoric and molybdotungstophosphoric HPCs substituted by Ni or Cu.The intermediate...Three new Dawson-type HPCs:K14·24H2O,K15H3·26H2O and K15H3·27H2O were synthesized for the first time.They are tungstophosphoric and molybdotungstophosphoric HPCs substituted by Ni or Cu.The intermediate product K10Na2H2P2W16O60 was synthesized from Na2WO4·2H2O and Na4HPO4·12H2O.The structures of the compounds were confirmed by IR,UV,XAFS and elemental analysis.展开更多
文摘The bimetallic catalyst Ru-Pt/ γ -Al 2O 3 was prepared by impregnating H 2PtCl 6 and RuCl 3 aqueous solution in the presence of PVP(40 000). Its catalytic performance in selective hydrogenation of \{ p -chloronitrobenzene\}( p -CNB) was studied. The results indicate that the activity of Ru-Pt/ γ -Al 2O 3[\{ n (ruthenium)\}∶ n (platinum)=4∶1] is much higher than that of Ru/ γ -Al 2O 3,while the amount of dehalogenation product(aniline) and other by-products are much fewer than that by using Pt/ γ -Al 2O 3 as the catalyst. There is synergistic effect of ruthenium and platinum in bimetallic catalyst for selective hydrogenation of p -CNB. Under the reaction conditions t =50 ℃, p H 2 = 1.0 MPa, reaction time 60 min,\{ n (substrate)∶\} n (total amount of metal content)=1000∶1,the conversion of p -CNB and the selectivity to p -chloroaniline( p -CNA) by using Ru-Pt/ γ -Al 2O 3 as the catalyst are 48.2% and 85.9%,respectively. The effect of other metal cations(introduced to the reaction system with the corresponding metal chloride solution) on the reaction was investigated. It was found that catalytic performance of Ru-Pt/ γ -Al 2O 3 could be greatly improved by modfication of some metal cations. When Co 2+ and Ni 2+ were used as modifiers for the catalyst Ru-Pt/ γ -Al 2O 3 under above mentioned reaction conditions,the conversions of p -CNB increase to 74.5% and 87.8%,as well as the selectivities of p -CAN increase to 98.9% and 99.4%,respectively. Fe 3+ and Sn 4+ were the best modifiers for Ru-Pt/ γ -Al 2O 3 under the same reaction conditions. The conversions of p -CNB and the selectivities of p -CAN can reach 100% and >99.0%,respectively. However,the catalysts can be poisoned by Zn 2+ and Sn 2+ .
文摘Using Zn（SO4）2·7H2O and H2C2O4·2H2O as raw materials,nanometer ZnO was prepared by liquid-phase precipitation method,the synthetic process and the properties of the product were studied by XRD,TG-DTA,TEM and IR.Ultrasonic washing with 0.05 mol·L-1 H2C2O4 solution,vacuum dry to ZnC2O4·2H2O precusor can improve the powder properties notably.The product ZnO crystalline has hexagonal strcture and an anaverage diameter of 23 nm with good dispersity and spherical shape.
文摘Three new Dawson-type HPCs:K14·24H2O,K15H3·26H2O and K15H3·27H2O were synthesized for the first time.They are tungstophosphoric and molybdotungstophosphoric HPCs substituted by Ni or Cu.The intermediate product K10Na2H2P2W16O60 was synthesized from Na2WO4·2H2O and Na4HPO4·12H2O.The structures of the compounds were confirmed by IR,UV,XAFS and elemental analysis.
