共查询到18条相似文献,搜索用时 171 毫秒
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以微孔HY浆液为母液,合成了介-微孔复合分子筛HY/MCM-41。通过XRD、BET和NH3-TPD等手段对复合分子筛进行表征,并考察其水热稳定性。结果表明,复合分子筛同时具有中孔分子筛MCM-41和微孔HY型沸石的特点,与纯MCM-41分子筛相比,酸性明显增强,水热稳定性提高。利用一段串联加氢裂化工艺,考察了复合分子筛的催化性能。200 mL固定床加氢装置评价结果表明,在控制原料>350 ℃馏分油转化率为75%的条件下,加氢裂化生成油C5+液收98.51%,最大量柴油馏分[(140~370) ℃]收率69.09%,<370 ℃中馏分油选择性80.5%,能满足工业装置最大量生产柴油的需要。 相似文献
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以碱处理β沸石作为硅铝源,以CTAB为模板剂,合成了β/MCM-41介孔-微孔复合分子筛,以其为载体制备Pd-β/MCM-41复合分子筛催化剂,利用XRD、N2吸附-脱附、NH3-TPD和XRF等技术对其进行了表征,并与γ-Al2O3、USY、ZSM-5等载体制备的催化剂比较了废食用油加氢裂解活性。结果表明:β/MCM-41复合分子筛同时具备β沸石和MCM-41分子筛的结构,β/MCM-41为载体时,Pd-β/MCM-41催化剂具有适宜的中强酸性中心,适宜的孔道分布结构,催化剂加氢裂解废食用油的活性最高。此外还考察了催化剂制备条件对废食用油加氢裂解反应的影响,结果表明:采用离子交换法制备负载量2%的Pd-β/MCM-41复合分子筛催化剂、焙烧温度为500 ℃时,催化剂对废食用油加氢裂解的效果最好。此时,原料油的转化率可以达到85.9%,生物汽油的收率可以达到16.4%,生物柴油的收率达到17.8%,且此催化剂水热稳定性较好,再生性能良好,工业化应用前景较好。 相似文献
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ZSM-5/MCM-41复合分子筛的微波合成及催化性能 总被引:1,自引:0,他引:1
用微孔沸石硅源法微波合成ZSM-5/MCM-41复合分子筛,采用XRD、BET和NH3-TPD技术对合成分子筛进行表征。结果表明,复合分子筛具有类MCM-41 的典型六方介孔结构,同时具有中孔和微孔结构,复合分子筛的总酸量介于HMCM-41酸量与HZSM-5酸量之间。利用脉冲微反装置考察合成分子筛的邻二甲苯异构化催化性能。结果表明,ZSM-5/MCM-41复合分子筛具有高于同硅铝比的MCM-41、ZSM-5和ZSM-5/MCM-41的机械混合物的催化活性。 相似文献
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采用后合成法制备复合分子筛Y/MCM-41,并以其为载体,用活性组分硝酸镍对其改性,制备Ni-Y/MCM-41催化剂,并利用XRD、BET、N2吸附-脱附对其进行表征。结果表明,复合分子筛同时具有微孔分子筛Y沸石和介孔材料MCM-41分子筛的特征。以硫质量分数为300μg/g的模拟油进行催化氧化脱硫实验,考察了Ni离子的负载量、反应温度、反应时间、催化剂用量、氧化剂用量等工艺条件对脱硫率的影响。结果表明:硝酸镍的负载量为10%,模拟油用量为20 m L,反应温度为70℃,反应时间为80 min,剂油比(催化剂与模拟油的质量比)为1∶70,V(H2O2)/V(油)=0.03时,脱硫率可达86.53%。 相似文献
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采用水热法合成出不含镍和含镍的硅基介孔分子筛.利用XRD、FT-IR、TPR、TEM和比表面孔径测定等手段对样品进行了表征.结果表明:合成出有序性好的介孔分子筛(MCM-41),550 ℃焙烧可以将模板剂有效去除,所合成介孔分子筛负载Pt后介孔有序性降低,但是介孔结构仍然存在.苯催化加氢反应研究表明:不含Ni的介孔分子筛不具有加氢活性,当将其负载Pt后具有苯加氢催化活性;含Ni介孔分子筛本身具有苯加氢活性,含Ni介孔分子筛负载Pt后苯加氢催化活性有较大的提高,所有样品的环己烷选择性都接近100 %,说明含Ni介孔分子筛可以直接作为苯加氢反应的催化剂或作为苯加氢催化剂良好的载体. 相似文献
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以丝光沸石分子筛为硅铝源,通过碱液处理和表面活性剂的自组装作用,水热条件下合成了MOR/MCM-41复合分子筛。通过XRD、SEM、TEM、N2吸附/脱附和水热稳定性处理等手段对合成的复合材料进行了表征。结果表明,复合材料不仅保留了原丝光沸石晶体的规则形貌,同时兼具微孔分子筛MOR和介孔分子筛MCM-41的特征,且介孔(20~30 nm)在微孔分子筛中较均匀地分布。水热处理测试结果表明,MOR/MCM-41复合分子筛具有较高的水热稳定性,水热处理100 h后介孔结构依然存在。 相似文献
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以氢氧化钠溶液处理微孔沸石ZSM-5来提供硅铝源,合成了ZSM-5/MCM-41复合结构型分子筛。采用XRD、N2吸附脱附、TEM等方法对其进行了表征,考察了其水热稳定性。实验结果表明,碱处理合成的ZSM-5/MCM-41同时具有微孔孔道和介孔孔道结构,并具有优于介孔MCM-41分子筛的水热稳定性。以ZSM-5/MCM-41为载体负载三氧化钨后应用于噻吩/正辛烷模拟油体系,双氧水为氧化剂,催化氧化脱硫,WO3-ZSM-5/MCM-41(三氧化钨质量分数为10%)表现出良好的催化性能,脱硫率可达到93.6%。 相似文献
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A Beta/MCM-41 composite zeolite with a stepwise-distributed pore structure was prepared with a silica-alumina source originated from alkaline treatment of zeolite Beta. The material was characterized by various techniques. The results indicated that this composite possesses a mesopore system of MCM-41 and the microporous structure of Beta zeolite. Hydrothermal stability and acidity was improved over MCM-41 due to the introduction of Beta building units into the mesopore walls. The composite was used as the support of a Pd-Pt catalyst for the hydrogenation of naphthalene in the presence and absence of 4, 6-dimethyldibenzothiophene. It was demonstrated that the catalyst has an enhanced activity and sulfur tolerance during naphthalene hydrogenation. 相似文献
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Da Jian-Wen Song Chun-Min Qian Ling Su Jian-Ming Xu Xing-Zhong 《Journal of Porous Materials》2008,15(2):189-197
MCM-41 zeolite in the grade of 600 kg was successfully synthesized and the MCM-41 added FCC catalyst was firstly prepared.
The results indicate that the pilot samples of mesoporous Al-MCM-41 bear the typically uniform mesopore structure and considerable
acidity and hydrothermal stability. The MCM-41 added FCC catalyst is positively capable to crack heavy oil feedstock, in which
the yields of the diesel and lighter oil increased 1.85 and 3.47%, respectively and coke yield decreased 0.29%. Commercial
application in FCCU indicate that optimization of nanopores of MCM-41 added faujasite zeolite might result in an industrial
process to design novel FCC catalysts. 相似文献
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Yuping Li Wei Zhang Xiaoli Wang Ying Zhang Tao Dou Kechang Xie 《Journal of Porous Materials》2008,15(2):133-138
A Beta/MCM-41 composite has been synthesized with a new method by using well-crystallized zeolite Beta as silica and aluminum
source. The prepared composite was characterized by XRD, FTIR, N2 adsorption/desorption at 77 K, FE-SEM, DTG, 29Si MAS NMR spectral techniques. It was shown that the composite consisted of a highly ordered mesoporous MCM-41 phase and
a zeolite Beta phase. Its hexagonal mesoporous structure was still retained after statically treated for 120 h in boiling
water. In contrast, the structure of generally synthesized Al-MCM-41 nearly completely collapsed. This might be attributed
to the assembly of the dissolved fragments such as the first and/or secondary structural units of zeolite Beta into the mesoporous
structure around surfactant micelles. This is supported by the catalytic result that the prepared composite showed higher
activity and selectivity for medium fraction in hydrocracking of Daqing vacuum residue than the parent zeolite Beta, the Al-MCM-41
as well as the mechanical mixture of these two materials. 相似文献
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按n(SiO2)∶n(Na2O)∶n(Al2O3)∶n(H2O)=1∶1.5∶0.5∶100加料,在90℃下水热晶化3 h合成NaA微孔分子筛,再按n(SiO2)∶n(NaOH)∶n(CTAB)∶n(H2O)=1∶0.3∶0.3∶90依次添加到NaA微孔分子筛中,于110℃下水热晶化24 h合成NaA/MCM-41微介复合分子筛,并采用XRD、SEM(EDS)和TEM等方法对其进行了表征。吸附阳离子红X-5GN模拟染料废水结果表明,在50 mLρ(阳离子红X-5GN)=20 mg/L的水溶液中,NaA/MCM-41微介复合分子筛的投加量为0.6 g/L、pH=6、振荡时间为60 min时,脱色率可达到96.4%,比NaA分子筛和MCM-41介孔分子筛独自吸附脱色效果要好。 相似文献
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The objective of this work is to give a comparative characterization of aluminosilicate MCM-41 and zeolite Y, in particular with respect to acidity and catalytic properties in hydrocarbon cracking. These studies are compared to a well investigated amorphous aluminosilicate, based on the fact that the new mesoporous MCM-41 materials are a mixture of ordered material with amorphous pore walls. Characterization of differently treated MCM-41 materials and zeolite Y for comparison by N2 sorption, XRD, TPAD (Temperature Programmed Ammonia Desorption) with in situ FT-IR in combination with catalytic testing by MAT (Micro Activity Test) is discussed. Combination of the characterization data and the catalytic testing gives an interesting explanation of the surface properties especially in comparison with zeolite Y. 相似文献
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Self-bonded zeolite Beta/MCM-41 composite spheres were prepared using a two-step synthesis procedure. In the first step, mesoporous zeolite Beta spheres were obtained using anion exchange resin as macrotemplate. In the second step, the MCM-41 or Al-MCM-41 was grown both on sphere surfaces and in the pore structure of the pre-formed zeolite Beta spheres. Finally, the templating agents used in the synthesis of mesophase were removed by calcination leaving behind self-bonded Beta/MCM-41 composite spheres. Beta/MCM-41 composites were characterized by XRD, SEM and nitrogen adsorption measurements. Materials with controlled macroshape, composition and complex porosity were prepared by the approach. 相似文献
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High activity in catalytic cracking of large molecules over a novel micro-micro/mesoporous silicoaluminophosphate 总被引:1,自引:0,他引:1