共查询到16条相似文献,搜索用时 125 毫秒
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JIANG Fu-Yi LIU Rui-Cui DU Wei YANG Dong-Mei HAN Jian-Ru 《结构化学》2007,26(9):1087-1091
Large AlPO4-5 molecular sieve single crystals with high optical quality were synthesized hydrothermally by using TPA as template. As-synthesized crystals were calcined under O2 atmosphere to remove the organic templates in the channels. Disperse-Red-1 (DR1) and p-nitroaniline (pNA) molecules have been successfully incorporated into the one-dimensional channels of AlPO4-5 single crystals respectively by means of vapor phase diffusion. XRD patterns reveal that the loading of organic molecules has not destroyed the structures of AlPO4-5 crystals. Polarizing microscope and SHG results indicate that the DR1 and pNA molecules are well aligned in a preferred direction along the crystal channels. The different polarization-dependence SH intensity shows that different SHG processes occur in the DR1- and pNA-loaded AlPO4-5 crystals. 相似文献
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C5烷烃分子在AlPO4-5分子筛中吸附的分子模拟研究 总被引:3,自引:0,他引:3
采用分子水平计算机模拟方法研究了环戊烷、正戊烷和2-甲基丁烷在AlPO4-5分子筛中的吸附,得到了有关吸附平衡常数、吸附热、吸附等温线以及平均势能等。结果表明,在373 K,2-甲基丁烷的饱和吸附量高于其他两种异构体;473 K,环戊烷的饱和吸附量高于其他两种异构体;573 K,在所测试的压力范围内,环戊烷的吸附量都高于其他两种异构体,2-甲基丁烷的吸附量高于正戊烷。C5烷烃分子在AlPO4-5中吸附量的不同是由于他们在分子筛中的排列方式不同而引起的。低吸附量时C5烷烃分子平均势能不随吸附量变化;高吸附量时平均势能随着吸附量的增加而降低;而2-甲基丁烷和环戊烷分子的平均势能变化更加明显。 相似文献
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AlPO4-5分子筛模板剂的量子化学计算 总被引:4,自引:0,他引:4
以23种有机分子作为模板剂用于AlPO4-5分子筛的合成,利用分子图形技术研究这些有机分子的形状和尺寸,采用量子化学PM3方法研究这些有机分子的电子性质,计算它们与AlPO4-5分子筛骨架模型簇之间的相互作用能。结果表明,量子化学计算数据可以作为寻找合成AlPO4-5分子筛新型模板剂时的重要参考依据。 相似文献
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ZSM-5(核)/AlPO4-5(壳)双结构分子筛的合成与催化裂化性能 总被引:7,自引:0,他引:7
采用X射线衍射、扫描电镜、X射线能量散射谱、红外光谱和核磁共振等多种物化方法对合成的ZSM-5(核)/AlPO4-5(壳)双结构分子筛进行了表征,证明这种材料具有以ZSM-5为核层、以AlPO4-5为壳层的双结构特征.考察了合成条件对ZSM-5(核)/AlPO4-5(壳)分子筛形貌的影响,发现ZSM-5分子筛的加入方式对产物的形貌有较大影响.重油裂化反应结果表明,ZSM-5(核)/AlPO4-5(壳)双结构分子筛的催化性能比ZSM-5和ZSM-5/AlPO4-5机械混合分子筛样品好,表现为原油转化率和低碳烯烃、汽油及柴油收率提高. 相似文献
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The aluminophosphate molecular sieve VPI-5 has received much attention as a new structure containing one-dimensional circular pores circumscribed by 18 tetrahedral atoms. The AlPO_4-8 is another new type of structure which was found to contain 1 4-ring open pores. Recently, we have successfully synthesized the molecular sieves of VPI-5 and AlPO_4-8, and found that the mixture of VPI-5 and AlPO_4-8 was easily formed under similar conditions, and VPI-5 can be converted to AlPO_4-8 by dehydration via heating. It is suggested that there exists relationship between the structures of VPI-5 and A1PO_4-8. Therefore, the study on the transition and relationship between VPI-5 and A1PO_4-8 is very important for designing and preparing new molecular sieves with new structures. 相似文献
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H(Mg,Co)AlPO4—5杂原子分子筛的酸性质测定 总被引:3,自引:0,他引:3
以红外光谱和程序升温脱附法研究了H(Mg,Co)AlPO_4-5分子筛的酸性,样品红外谱图中的3820和3680cm~(-1)谱峰分别归属于v_(Al—OH)和v_(p—OH),而3660~3568cm~(-1)谱峰则分别归属于HMgAlPO_4-5和HCoAlPO_4-5分子筛的M(OH)P(M=Mg,Co)基团的振动,酸强度顺序为:Co(OH)P>Mg(OH)P>P(OH)>Al(OH),吡啶吸附的红外光谱揭示,H(Mg,Co)AlPO_4-5分子筛具有较高酸强度的B酸和L酸中心。NH_3-TPD表明分子筛的酸强度顺序为H(Co)AlPO_4-5>H(Mg)AlPO_4-5>>AlPO_4-5。 相似文献
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The micropores and surface characteristics of aluminophosphate-type zeolite, AlPO4-5, were analyzed by examining the adsorption behavior of water and other adsorbates. Water adsorption on AlPO4-5 occurred on both structural defects and nonpolar surfaces. Adsorption on structural defects, accompanied by high heats
of adsorption, is attributed to adsorption to surface hydroxyls. Water adsorption increased steeply at a certain relative
pressure depending on the adsorption temperature, and this was considered attributable to capillary condensation. The contact
angle of water on AlPO4-5 micropore surfaces can be determined quantitatively by applying the Kelvin equation. The surface free energy of AlPO4-5 calculated on the basis of the contact angle was revealed to be about 120 mJ/m2, in agreement with accepted values of the dispersion component of the surface free energy of metal oxides. Adsorption heat
values of adsorbates with different polarities indicate that the AlPO4-5 surface is essentially nonpolar and interacts only with dispersion interaction. In the case of n-hexane the contact angle was assumed to be zero, showing high affinity with the result of enhanced adsorption due to pore
filling.
Received: 21 May 1998 Accepted: 28 July 1998 相似文献
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磷酸铝分子筛AlPO4-12的合成与性能研究 总被引:5,自引:0,他引:5
用乙二胺作模报剂,在水热体系中合成了磷酸铝分子筛AIPO4-12,考察了反应混合物的初始PH值和乙二胺用量对产物结晶相的影响,产品的化学组成与文献值吻合。用XRD、SEM、IR、DTA、化学分析和吸附等方法,对样品进行了表征及物化性能的研究,用丙酸与正丁醇的酯化为典型反应,考究了AIPO4-12分子筛的催化性能,实验结果表明,AIPO4-12具有良好的吸附性能、很高的热稳定性(骨架倒塌温度为997 相似文献