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Ce-MCM-48介孔分子筛的合成、表征和催化性能 总被引:7,自引:0,他引:7
尝试以混合模板剂pH调节水热合成掺入铈的介孔分子筛CeMCM48,并采用X射线衍射、高分辨透射电镜、紫外可见漫反射、X射线荧光光谱、氮气吸附脱附测试手段对样品进行表征.结果表明,新合成的掺铈介孔材料仍保持立方介孔的有序结构,有序性及吸附性能得到改善.所合成的掺铈的立方介孔分子筛对环己烷的液相氧化反应的催化活性和选择性较高.CeMCM48催化环己烷氧化反应的转化率较MCM48催化的转化率提高了8.3%~14.2%,对主要产物的选择性提高了63.4%~68.8%. 相似文献
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两种新型Cu(Ⅱ)混配聚合物的合成和晶体结构 总被引:4,自引:0,他引:4
用水热法合成了2种新型的配位聚合物[Cu(4-Pya)(2,4-PydcH)]n(1)和[Cu2(2,6-Ndc)2(Bpobp)]n(2)(4-Hpya=4-吡啶羧酸,2,4-pydcH2=吡啶-2,4-二羧酸,2,6-H2ndc=2,6-萘二酸,Bpobp=4,4′-二(3-吡啶羟基)-联苯胺),并测定了其晶体结构。1属于正交晶系,Pna21空间群,晶胞参数a=2.138 20(2) nm,b=0.990 60(1) nm,c=0.608 40(1) nm,V=1.288 65(3) nm3,Z=4,R1=0.023,wR2=0.067。2属于三斜晶系,P1空间群,晶胞参数a=0.810 2(3) nm,b=0.997 9(4) nm,c=1.270 5(5) nm,α=86.282(6)°,β=73.517(5)°,γ=89.107(6)°,V=0.982 9(7) nm3,Z=2,R1=0.082,wR2=0.160 2。配合物1为三维结构,其中五配位的铜为扭曲的四方锥构型。配合物2展示了由车轮状二铜结构单元连接而成的非互穿的三维网络结构。 相似文献
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A series of NiAlPO4–5 molecular sieves have been hydrothermally synthesized and shown high and stable activity in the direct amination of benzene to aniline with hydroxylamine hydrochloride as aminating agent. The as‐synthesized and calcined samples were investigated with XRD, SEM, TG, BET, NH3‐TPD and FT‐IR to explore the crystalline, coordination and location of the incorporated transition metal ions. The results indicated that nickel ions were incorporated into the framework of AlPO4–5 and the as‐synthesized catalysts were highly crystalline, and possessed good thermal stability. Among them, Ni(0.3)AlPO4–5 showed the highest catalytic activity for the direct amination of benzene with the highest aniline yield of 73.2% and 100.0% selectivity to aniline. After the catalyst was reused for 5 times, the activity remained little change. 相似文献
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通过2,2',6,6’-联苯四酸与相应金属硝酸盐和第二配体的水热反应合成了2个具有不同结构的配位聚合物[Co(bta)0.5(2,2’-bipy)(H2O)]n(1)和{[Cd2,(bta)(H2biim)2(H2O)]·H2O}n(2)(H4bta=2,2’,6,6’-联苯四酸,2,2'-bipy=2,2’-联吡啶,H2biim=1H,1’H-2,2’-联咪唑),并测定了其晶体结构.1和2都是一维链结构,并且1和2都属于单斜晶系,P21/c空间群.bta配体在1和2中分别采取η6,μ4六齿和η5,μ4-五齿配位模式,同时bta配体中2个苯环的夹角在化合物1和2中分别是64.80°和64.86°.1与2分别在170℃和120℃以下保持热稳定性. 相似文献
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Jin Zhongxiu Tong Hongwu Yong Guoping Sheng Liangquan Liu Qingliang Liu Shaomin 《化学物理学报(中文版)》2005,18(6):1057-1061
Cerium incorporated MCM-48 molecular sieves have been hydrothermally synthesized by both a mixed template and a variable pH approach. The samples were characterized by various physicochemical methods, including X-ray diffraction, transmission electron microscopy, diffuse reflectance UV-vis spectroscopy, XRF spectroscopy, nitrogen adsorption. These results reveal that cerium is incorporated in MCM-48 in the form of well-dispersed tetra-coodinated cerium ion. Maintaining the proper concentration of cerium and adjusting the pH allows for a more ordered structure with a much higher specific surface area than that of MCM-48. Ce-MCM-48 was employed in the liquid phase oxidation of cyclohexane with aqueous H2O2. The results showed that Ce-MCM-48 is more active as a catalyst for the liquid phase oxidation of cyclohexane. The oxidation conversion catalyzed by Ce-MCM-48 is 8.3 %-14.2% higher than that catalyzed by MCM-48 and the selectivity for the main products increase by 63.4%-68.8%. Accordingly, Ce-MCM-48 has been shown to have important potential applications. 相似文献
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通过水热法合成得到1个以1,8-萘二酸(1,8-nap)为配体的Ba(Ⅱ)配合物 [Ba(μ5-1,8-nap)]n(1)。X射线单晶衍射测定结果表明:配合物属于单斜晶系,空间群P21/c。配合物最小不对称单元由1个九配位的钡原子和1个1,8-萘二酸配体构成。每个1,8-萘二酸配体连接五个钡原子,每个钡原子连接五个1,8-萘二酸配体,在(100)平面上形成二维双层结构。此外,对配合物的固态荧光性质做了测定,结果显示其在紫光区有荧光发射。 相似文献
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通过2,2′,6,6′-联苯四酸与相应金属硝酸盐和第二配体的水热反应合成了2个具有不同结构的配位聚合物[Co(bta)0.5(2,2′-bipy)(H2O)]n(1)和{[Cd2(bta)(H2biim)2(H2O)].H2O}n(2)(H4bta=2,2′,6,6′-联苯四酸,2,2′-bipy=2,2′-联吡啶,H2biim=1H,1′H-2,2′-联咪唑),并测定了其晶体结构。1和2都是一维链结构,并且1和2都属于单斜晶系,P21/c空间群。bta配体在1和2中分别采取η6,μ4-六齿和η5,μ4-五齿配位模式,同时bta配体中2个苯环的夹角在化合物1和2中分别是64.80°和64.86°。1与2分别在170℃和120℃以下保持热稳定性。 相似文献