Coral reef-like Ni/Al2O3 catalysts were prepared by co-precipitation of nickel acetate and aluminium nitrate with sodium carbonate aqueous solution in the medium of ethylene glycolye.Methanation of syngas was carried ...Coral reef-like Ni/Al2O3 catalysts were prepared by co-precipitation of nickel acetate and aluminium nitrate with sodium carbonate aqueous solution in the medium of ethylene glycolye.Methanation of syngas was carried out over coral reef-like Ni/Al2O3 catalysts in a continuous flow type fixed-bed reactor.The structure and properties of the fresh and used catalysts were studied by SEM,N2 adsorption-desorption,XRD,H2-TPR,O2-TPO,TG and ICP-AES techniques.The results showed that the coral reef-like Ni/Al2O3 catalysts exhibited better activity than the conventional Ni/Al2O3-H2O catalysts.The activities of coral reef-like catalysts were in the order of Ni/Al2O3-673Ni/Al2O3-573Ni/Al2O3- 473Ni/Al2O3-773.Ni/Al2O3-673-EG catalyst showed not only good activity and improved stability but also superior resistance to carbon deposition,sintering,and Ni loss.Under the reaction conditions of CO/H2(molar ratio)=1:3,593 K,atmospheric pressure and a GHSV of 2500 h-1,CH4 selectivity was 84.7%,and the CO conversion reached 98.2%.展开更多
The 4% Ni-Al2O3catalysts prepared by coprecipitation method calcined at different temperature was tested by propane selective catalytic reduction of nitric oxide(NO) in excess oxygen.Catalyst calcined at 550 ℃ show...The 4% Ni-Al2O3catalysts prepared by coprecipitation method calcined at different temperature was tested by propane selective catalytic reduction of nitric oxide(NO) in excess oxygen.Catalyst calcined at 550 ℃ showed the highest activity for selective catalytic reduction of NO and the NO conversion was approached to 100 % at 500 ℃.The Ni-Al2O3 catalyst was characterized by XRD,temperature-programmed reduction with H2(H2-TPR) and BET techniques.Based on the characterization results,with the increase of calcinations temperature,NiO gradually changes to the surface aluminate phase containing highly dispersed nickel metal cations in Al2O3 matrix,which was responsible for the high activity of catalyst calcined at 550 ℃.At higher calcination temperature,the decrease of surface areas results in the decrease of the activities of the catalyst for NO selective catalytic reduction by propane.展开更多
Abstract: An alloy steel/alumina composite was successfully fabricated by pressureless infiltration of X10CrNil8-8 steel melt on 30% (mass fraction) Ni-containing alumina based composite ceramic (Ni/Al2O3) at 1 6...Abstract: An alloy steel/alumina composite was successfully fabricated by pressureless infiltration of X10CrNil8-8 steel melt on 30% (mass fraction) Ni-containing alumina based composite ceramic (Ni/Al2O3) at 1 600 ℃. The infiltration quality and interfacial bonding behavior were investigated by SEM, EDS, XRD and tensile tests. The results show that there is an obvious interfacial reaction layer between the alloying steel and the Ni/Al2O3 composite ceramic. The interfacial reactive products are (FexAly)3O4 intermetallic phase and (AlxCry)2O3 solid solution. The interracial bonding strength is as high as about 67.5 MPa. The bonding mechanism of X10CrNi 18-8 steel with the composite ceramic is that Ni inside the ceramic bodies dissolves into the alloy melt and transforms into liquid channels, consequently inducing the steel melt infiltrating and filling in the pores and the liquid channels. Moreover, the metallurgical bonding and interfacial reactive bonding also play a key role on the stability of the bonding interface.展开更多
基金financially supported by Independent Research Subject from Ministry of Science and Technology of China(No.2008BWZ005)
文摘Coral reef-like Ni/Al2O3 catalysts were prepared by co-precipitation of nickel acetate and aluminium nitrate with sodium carbonate aqueous solution in the medium of ethylene glycolye.Methanation of syngas was carried out over coral reef-like Ni/Al2O3 catalysts in a continuous flow type fixed-bed reactor.The structure and properties of the fresh and used catalysts were studied by SEM,N2 adsorption-desorption,XRD,H2-TPR,O2-TPO,TG and ICP-AES techniques.The results showed that the coral reef-like Ni/Al2O3 catalysts exhibited better activity than the conventional Ni/Al2O3-H2O catalysts.The activities of coral reef-like catalysts were in the order of Ni/Al2O3-673Ni/Al2O3-573Ni/Al2O3- 473Ni/Al2O3-773.Ni/Al2O3-673-EG catalyst showed not only good activity and improved stability but also superior resistance to carbon deposition,sintering,and Ni loss.Under the reaction conditions of CO/H2(molar ratio)=1:3,593 K,atmospheric pressure and a GHSV of 2500 h-1,CH4 selectivity was 84.7%,and the CO conversion reached 98.2%.
文摘The 4% Ni-Al2O3catalysts prepared by coprecipitation method calcined at different temperature was tested by propane selective catalytic reduction of nitric oxide(NO) in excess oxygen.Catalyst calcined at 550 ℃ showed the highest activity for selective catalytic reduction of NO and the NO conversion was approached to 100 % at 500 ℃.The Ni-Al2O3 catalyst was characterized by XRD,temperature-programmed reduction with H2(H2-TPR) and BET techniques.Based on the characterization results,with the increase of calcinations temperature,NiO gradually changes to the surface aluminate phase containing highly dispersed nickel metal cations in Al2O3 matrix,which was responsible for the high activity of catalyst calcined at 550 ℃.At higher calcination temperature,the decrease of surface areas results in the decrease of the activities of the catalyst for NO selective catalytic reduction by propane.
基金Project(2009ZM0296) supported by the Fundamental Research Funds for the Central Universities in China
文摘Abstract: An alloy steel/alumina composite was successfully fabricated by pressureless infiltration of X10CrNil8-8 steel melt on 30% (mass fraction) Ni-containing alumina based composite ceramic (Ni/Al2O3) at 1 600 ℃. The infiltration quality and interfacial bonding behavior were investigated by SEM, EDS, XRD and tensile tests. The results show that there is an obvious interfacial reaction layer between the alloying steel and the Ni/Al2O3 composite ceramic. The interfacial reactive products are (FexAly)3O4 intermetallic phase and (AlxCry)2O3 solid solution. The interracial bonding strength is as high as about 67.5 MPa. The bonding mechanism of X10CrNi 18-8 steel with the composite ceramic is that Ni inside the ceramic bodies dissolves into the alloy melt and transforms into liquid channels, consequently inducing the steel melt infiltrating and filling in the pores and the liquid channels. Moreover, the metallurgical bonding and interfacial reactive bonding also play a key role on the stability of the bonding interface.
基金supported by the National Natural Science Foundation of China(21703194)the Natural Science Foundation of Jiangsu Province(BK20171168,BK20171169)+2 种基金Natural Science Foundation of Jiangsu Higher Education Institutions of China(17KJB530010,17KJB150038 and18KJA430015)Key Research Project of Social Development of Xuzhou(KC17154)Research Project of Xuzhou University of Technology(XKY2017217)