A series of catalysts,hexaaluminates LaCexFe1-xAl11O19（x=0,0.2,0.4,0.6,0.8,1） were prepared by the co-precipitation method.The influences of the Ce doped on structure and catalytic performance of catalysts were studied by XRD,FT-IR,H2-TPR,UV-DRS,XPS,EC（Electrical conductivity） and methane combustion activity test.The result shows that rare earth Ce species are more readily to exist in the form of CeO2over the catalysts than to enter the bulks of LaFeAl11O19hexaaluminates to substitute Al and Fe.Compared with catalyst LaFeAl11O19 without Ce doped,the Ce doped catalysts are being higher catalytic activity for methane combustion.Under reaction conditions of 4800h-1air velocity,and LaCe0.8Fe0.2Al11O19 showed the highest activity.It indicated that the CeO2,was contributed to improve the catalytic activity of LaCe0.8Fe0.2Al11O19 .Meanwhile,with Ce-containing increasing,the FT-IR spectra of each sample move forward the direction of higher wave-numbers slightly.Catalysts reduced proceeding becomes difficult.XPS and EC（Electrical conductivity） tests found that charge density of Fe3+ was added and Fe2P3 binding energy shifted to minus direction,electrical conductivity performance revealed that La-Fe hexaaluminates belonged to n-type semiconductor.After doped Ce,we found that electrical conductivity decline.When content of Ce reaches to x=0.8,the sample’s electrical conductivity becomes zero.
利用1-苯基-3-(2,4,6-三甲基苯基)丙烯酮和2-肼-9-芳基邻菲咯啉的缩合反应合成了一系列2-[N-(3-苯基-5-(2,4,6-三甲基苯基)吡唑啉)]-9-芳基邻菲咯啉类配体(L1-L4),分别与N iC l2反应得到了相应的配合物[N iC l2L](1-4),对配体和配合物进行了表征,并用X-单晶衍射分析了配合物4的晶体结构,表明N i中心为五配位的四方锥构型.化合物l-4在MAO存在下对乙烯齐聚表现出良好的催化活性.在1 MPa乙烯压力下,化合物4的催化活性最好,高达2.52×105g mo-l1h-1.讨论了配体空间位阻及反应条件对乙烯齐聚活性的影响,发现邻菲咯啉的9-位位阻对催化活性影响更明显.
