The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were...The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were investigated by using X-ray diffractometry(XRD), UV Raman spectroscopy, TEM, and SEM. It is observed that Ni doping can promote the phase transition and grain size growth of TiO2. Moreover, the propagation of the rutile phase from the bulk into the surface region of TiO2 is increased when the Ni doping amount reaches up to 3%. However, in Ni/TiO2, it is found out that the surface and bulk phase transformation of TiO2 can be inhibited after impregnation of 1% of Ni on the TiO2. Compared with the co-precipitation method, Ni species may be more enriched in the surface of the Ni/TiO2 sample upon adoption of the impregnation method, and the direct contact of anatase particles of TiO2 is avoided. As a consequence, the phase transition in the surface and bulk region of TiO2 can be effectively inhibited by Ni loading. Additionally, the activity of the photocatalytic degradation of RhB on the 3Ni-TiO2-600 ℃ sample is higher than that on the 3 Ni/TiO2-600 ℃ sample. The phase junction formed between anatase and rutile in the surface region of 3Ni-TiO2-600 ℃ may the main reason for its high photocatalytic activity.展开更多
The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy...The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy X-ray diffraction,and electron probe micro-analysis techniques.At high temperature,eutectoid decomposition R_2(Ni,M)_(17)→R(Ni,M)_5+x-Ni(M) takes place in these two pseudo-ternary compounds,in the composition range x=0.6～1.0 and y=0.3～1.0,respectively.When x(or y)≤0.2,both Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B are single phase tetragonal.The phase constitutents of these two systems at room tempera- ture are similar in the composition range 0.6≤x(or y)≤1.0.展开更多
Pattern recognition method is used for the investigation of stability,region of filled Ti_2Ni phases in multi-dimensional bond-parameter space.The filling of C,N and O atoms into T_6 octahedra consisting of atoms of e...Pattern recognition method is used for the investigation of stability,region of filled Ti_2Ni phases in multi-dimensional bond-parameter space.The filling of C,N and O atoms into T_6 octahedra consisting of atoms of earhy-transition elements makes the expansion of the stability region of Ti_2Ni phase,and the relative stability of AI_2Cu and MoSi_2 type com- pounds decreases after the introduction of non-metallic elements such as C,N and O.展开更多
The 80%Ni2P/Al2O3 catalysts were prepared by the phosphidation of corresponding 80%Ni/Al2O3 with triphenylphosphine in liquid phase and compared with the 60%Ni2P/Al2O3 for hydrotreating reactions. Both the60%Ni2P/Al2O...The 80%Ni2P/Al2O3 catalysts were prepared by the phosphidation of corresponding 80%Ni/Al2O3 with triphenylphosphine in liquid phase and compared with the 60%Ni2P/Al2O3 for hydrotreating reactions. Both the60%Ni2P/Al2O3 and 80%Ni2P/Al2O3 in comparison exhibited the small and uniform Ni2 P particles（6.3 and8.4 nm,respectively）,high CO uptakes（305 and 345 μmol/g,respectively） and thus high activities for the hydrotreating reactions. After the hydrotreating reactions,the small and uniform Ni2 P particles were remained,although the CO uptakes on the used 60%Ni2P/Al2O3 and 80%Ni2P/Al2O3 were greatly decreased（to 68 and95 μmol/g,respectively） due to the incorporation of S into the Ni2 P surfaces. The 80%Ni2P/Al2O3 was found to be significantly more active than the 60%Ni2P/Al2O3 due to that the 80%Ni2P/Al2O3 possessed more,and more active Ni2 P sites than the 60%Ni2P/Al2O3,probably due to the less S incorporated in the 80%Ni2P/Al2O3 than in the 60%Ni2P/Al2O3 during the hydrotreating reactions.展开更多
The Ni2P/MgAlO catalysts with different MgO/Al2O3 ratios were prepared by the phosphidation of corresponding Ni/MgAlO catalysts with triphenylphosphine in liquid phase. It was found that the MgO/Al2O3 ratio affected t...The Ni2P/MgAlO catalysts with different MgO/Al2O3 ratios were prepared by the phosphidation of corresponding Ni/MgAlO catalysts with triphenylphosphine in liquid phase. It was found that the MgO/Al2O3 ratio affected the Ni2P/MgAlO catalysts significantly. The Ni2P/MgAlO catalyst with the MgO/Al2O3 ratio of 3 (w/w) exhibited the highly dispersed Ni2P particles (similar to 9 nm) with the highest CO uptake (344 mu mol/g) and thus the highest activities for the hydrotreating reactions. However, based on the CO uptakes on the used catalysts, the TOF values for the hydrodesulphurization of dibenzothiophene as well as those for the hydrogenation of tetralin on all the Ni2P/MgAlO catalysts were respectively similar, indicating that the MgO/Al2O3 ratio did not affect the intrinsic activities of Ni2P supported on the MgAlO support for the hydrotreating reactions. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.展开更多
基金financially supported by the National Natural Science Foundation of China (No. 20903054)sponsored by the Scientific Research Foundation for the Returned Overseas Chinese ScholarsState Education Ministry (The project is sponsored by SRF for ROCS, SEM)
文摘The Ni-modified TiO2 was synthesized using two methods including co-precipitation(Ni doped TiO2, Ni-TiO2) and wet impregnation(Ni loaded TiO2, Ni/TiO2). The surface and bulk crystalline phases of Ni-modified TiO2 were investigated by using X-ray diffractometry(XRD), UV Raman spectroscopy, TEM, and SEM. It is observed that Ni doping can promote the phase transition and grain size growth of TiO2. Moreover, the propagation of the rutile phase from the bulk into the surface region of TiO2 is increased when the Ni doping amount reaches up to 3%. However, in Ni/TiO2, it is found out that the surface and bulk phase transformation of TiO2 can be inhibited after impregnation of 1% of Ni on the TiO2. Compared with the co-precipitation method, Ni species may be more enriched in the surface of the Ni/TiO2 sample upon adoption of the impregnation method, and the direct contact of anatase particles of TiO2 is avoided. As a consequence, the phase transition in the surface and bulk region of TiO2 can be effectively inhibited by Ni loading. Additionally, the activity of the photocatalytic degradation of RhB on the 3Ni-TiO2-600 ℃ sample is higher than that on the 3 Ni/TiO2-600 ℃ sample. The phase junction formed between anatase and rutile in the surface region of 3Ni-TiO2-600 ℃ may the main reason for its high photocatalytic activity.
基金the National Natural Science Fundation of China.
文摘The melting behavior,solid state phase transformation and structure of pseudo-ternary compounds Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B were studied using differential thermal analysis,optical microscopy X-ray diffraction,and electron probe micro-analysis techniques.At high temperature,eutectoid decomposition R_2(Ni,M)_(17)→R(Ni,M)_5+x-Ni(M) takes place in these two pseudo-ternary compounds,in the composition range x=0.6～1.0 and y=0.3～1.0,respectively.When x(or y)≤0.2,both Nd_2(Fe_(1-x)Ni_x)_(14)B and Pr_2(Co_(1-y)Ni_y)_(14)B are single phase tetragonal.The phase constitutents of these two systems at room tempera- ture are similar in the composition range 0.6≤x(or y)≤1.0.
文摘Pattern recognition method is used for the investigation of stability,region of filled Ti_2Ni phases in multi-dimensional bond-parameter space.The filling of C,N and O atoms into T_6 octahedra consisting of atoms of earhy-transition elements makes the expansion of the stability region of Ti_2Ni phase,and the relative stability of AI_2Cu and MoSi_2 type com- pounds decreases after the introduction of non-metallic elements such as C,N and O.
基金supports from NSFC (21273105)MSTC (2013AA031703)NSFJC (BK20140596)
文摘The 80%Ni2P/Al2O3 catalysts were prepared by the phosphidation of corresponding 80%Ni/Al2O3 with triphenylphosphine in liquid phase and compared with the 60%Ni2P/Al2O3 for hydrotreating reactions. Both the60%Ni2P/Al2O3 and 80%Ni2P/Al2O3 in comparison exhibited the small and uniform Ni2 P particles（6.3 and8.4 nm,respectively）,high CO uptakes（305 and 345 μmol/g,respectively） and thus high activities for the hydrotreating reactions. After the hydrotreating reactions,the small and uniform Ni2 P particles were remained,although the CO uptakes on the used 60%Ni2P/Al2O3 and 80%Ni2P/Al2O3 were greatly decreased（to 68 and95 μmol/g,respectively） due to the incorporation of S into the Ni2 P surfaces. The 80%Ni2P/Al2O3 was found to be significantly more active than the 60%Ni2P/Al2O3 due to that the 80%Ni2P/Al2O3 possessed more,and more active Ni2 P sites than the 60%Ni2P/Al2O3,probably due to the less S incorporated in the 80%Ni2P/Al2O3 than in the 60%Ni2P/Al2O3 during the hydrotreating reactions.
基金Financial supports from NSFC(21273105)MSTC(2013AA031703)+1 种基金NSFJC(BK20140596)the fundamental research funds for central universities
文摘The Ni2P/MgAlO catalysts with different MgO/Al2O3 ratios were prepared by the phosphidation of corresponding Ni/MgAlO catalysts with triphenylphosphine in liquid phase. It was found that the MgO/Al2O3 ratio affected the Ni2P/MgAlO catalysts significantly. The Ni2P/MgAlO catalyst with the MgO/Al2O3 ratio of 3 (w/w) exhibited the highly dispersed Ni2P particles (similar to 9 nm) with the highest CO uptake (344 mu mol/g) and thus the highest activities for the hydrotreating reactions. However, based on the CO uptakes on the used catalysts, the TOF values for the hydrodesulphurization of dibenzothiophene as well as those for the hydrogenation of tetralin on all the Ni2P/MgAlO catalysts were respectively similar, indicating that the MgO/Al2O3 ratio did not affect the intrinsic activities of Ni2P supported on the MgAlO support for the hydrotreating reactions. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.
