共查询到19条相似文献,搜索用时 62 毫秒
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Co-Mo/SBA-15柴油加氢脱硫研究 总被引:3,自引:0,他引:3
以介孔分子筛SBA-15为载体,担载Co—Mo双金属活性组分制备了深度加氢脱硫催化剂。通过XRD和BET表征表明,负载金属后SBA-15分子筛仍然保持二维晶相结构,表面积略有下降。以直馏柴油为原料,在固定床反应器上评价了催化剂的脱硫反应活性的结果表明,SBA-15介孔分子筛Co—Mo的负载量为W(CoO)=5%,w(MoO3)=25%;脱硫适宜的反应条件为:反应温度360℃,压力4.0MPa,氢油体积比400.0,空速2.0h^-1。在此条件下,柴油硫含量可由1350μg/g降至39μg/g。 相似文献
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研究助剂La2O3对Ni/γ-Al2O3/堇青石结构化催化剂结构与性能的影响。采用悬浮液涂层法、活性组分浸渍法制备不同La2O3助剂含量的Ni/γ-Al2O3/堇青石结构化催化剂。通过BET、XRD、TPR、XPS对催化剂进行表征,发现不添加La2O3助剂时活性组分以NiAl2O4形式存在,添加La2O3助剂后则以NiAl2O4和NiO两种形式存在,易还原NiO的生成提高了催化剂的活性。添加La2O3助剂还能使催化剂的比表面积降低和孔尺寸增大,活性评价表明助剂La2O3存在适宜添加量,即La含量为3%。同时发现助剂La2O3对选择性的影响大于活性,La2O3具有结构助剂的特点。 相似文献
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工业堇青石打磨成适当大小的长方体,用草酸溶液沸煮预处理后作为整体式催化剂的载体,利用自动物理吸附仪和电子压力机分别考查了酸预处理条件对堇青石载体的比表面积、失重率以及机械强度的影响。实验结果表明用20%的草酸沸煮处理2 h时堇青石载体的失重率有所增加,可以在保证较强的机械强度前提下获得较为理想的比表面积。 相似文献
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采用溶胶-凝胶法制备了TiO2-Al2O3复合载体, 以柠檬酸(CA)为络合剂采用浸渍法制备了Ni2P负载的TiO2-Al2O3复合载体催化剂, 并用 X 射线衍射(XRD)、N2吸附比表面积(BET)测定技术对催化剂的结构和性质进行了表征, 考察了载体焙烧温度、催化剂焙烧温度、还原温度、还原压力对其进行的二苯并噻吩(DBT)加氢脱硫(HDS)性能的影响。结果表明, 升高载体焙烧温度有利于催化剂表面上活性物种的分散, 但焙烧温度过高会导致催化剂烧结, 适宜的载体焙烧温度为550℃。当还原温度为500~550℃时, 磷化镍主要以Ni12P5相形式存在, 且随着还原温度的升高, Ni12P5的衍射峰强度逐渐增强, 还原温度为700℃时, 可得到单一的Ni2P物相。载体焙烧温度为550℃, 催化剂焙烧温度为500℃, 还原温度为700℃, 常压还原制备的Ni2P/TiO2-Al2O3催化剂具有最好的活性。在360℃、3.0MPa、氢油体积比500、液时体积空速2.0h-1的条件下, 反应4h时, DBT转化率为99.5 %。 相似文献
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通过高温焙烧和氢氟酸瞬间蚀刻修饰堇青石蜂窝陶瓷骨架和孔壁表面结构,采用XRD、SEM、TEM表征修饰前后结构和形貌变化,探究陶瓷结构对机械强度、碳纳米管形貌结构及复合载体性质的影响,考察Pd/CNTs@CHC-HFn催化剂催化聚苯乙烯(PS)加氢性能及催化剂用量与加氢度的关系。结果表明,高温焙烧消除了骨架内部孔道,陶瓷表面变得平整密实;瞬间蚀刻增大了表面粗糙度,易于CNTs在表面生长,但蚀刻次数增加,导致蚀刻由表面向骨架内部侵入、CNTs在骨架内部生长,降低载体的机械强度。CNTs@CHC-HFn载体表面的CNTs可显著提高复合催化剂的加氢性能,其中加氢活性位Pd分布均匀,平均粒径为3.6 nm,当催化剂用量为3.0 g cat·(g PS)-1时,其中含0.378 g CNTs和0.054 g Pd,反应6 h加氢度可达100%。 相似文献
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采用固定床反应器,以自制的V-W-Ti-Si/堇青石为催化剂,在消除内外扩散影响的基础上,考察了氨选择性催化还原反应(NH_3-SCR)过程,建立了幂指数型的脱硝反应动力学模型,并通过线性拟合确定了模型参数。结果表明,在自制的V-W-Ti-Si/堇青石催化剂上,NO,NH_3和O_2的反应级数分别为0.93,0,0.24,活化能为25.99 kJ/mol,模型拟合的相对误差在10%左右,可用于指导柴油机尾气脱硝催化剂反应过程研究与开发。 相似文献
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Bo Wang Zhentao Chen Tao Jiang Jiahuan Yu Haoxuan Yang Aijun Duan Chunming Xu 《American Institute of Chemical Engineers》2022,68(5):e17577
Macromolecular organosulfur compounds encountered resistance when diffusing in catalyst pore channels during the hydrotreating process. Quantitative insights into the effects of the catalyst pore size and the reactant molecule size on the diffusivities can guide the optimization of the catalyst structures. Herein, a heavy oil macromolecular dibenzothiophene compound, 2,8-di-(4-pentyl phenyl)dibenzothiophene (2,8-DPPDBT), was synthesized. Three NiMo-supported SBA-15 based catalysts with different pore sizes, but similar active phase dispersions were controllably fabricated. The reaction network of 2,8-DPPDBT HDS was proposed. The diffusion behaviors of 2,8-DPPDBT, along with 2,8-dimethyl dibenzothiophene (2,8-DMDBT) and dibenzothiophene (DBT) in three SBA-15 pore channels, were systematically investigated through the reaction kinetic method. A restrictive factor, F(λ), was correlated by F(λ) = (1 − λ)8.5 to determine the relationship between the effective diffusivity and the ratio of the molecule-to-pore size (λ). This empirical correlation provided sound theoretical guidance on the design of highly efficient heavy oil hydrodesulfurization catalysts. 相似文献
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A series of the Pt-Sn/SBA-15 catalysts were prepared and their properties characterized by using X-ray powder diffraction (XRD), N2 adsorption-desorption, high resolution transmission electron microscope, X-ray photoelectron spectroscopy (XPS) and H2-temperature programmed reduction. Their performances in long chain alkane dehydrogenation were evaluated in a fixed-bed microreactor with dodecane as a model alkane. The results indicated that SBA-15 maintained the well-order mesoporous structure during the reaction. The performance of the catalyst was found not dominated by its textural properties, but by the molar ratio of Sn to Pt which governed the degree of Sn reduction. Owing to the highest degree of Sn reduction, 1% (by mass) Pt-1.8% (by mass) Sn/SBA-15 showed the best catalytic activity. At 0.1 MPa and 470℃, the molar ratio of hydrogen to alkane at 4, and liquid hourly space velocity (LHSV) 20 h^-1, the dodecane conversion is 10%, and the dodecene selectivity is about 70%. 相似文献
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以柠檬酸处理过的偏钒酸铵为钒源,采用后合成法制备出了V/SBA-15负载型催化剂,研究其在氧化苯乙烯制苯甲醛反应中的催化性能.结果表明,在钒负载量低于15%时,V/SBA-15仍保持SBA-15的高度有序的二维六方孔道结构,且具有较大的比表面积和孔体积,负载的活性组分金属钒氧化物均匀分布在介孔分子筛表面;在优化条件下催化氧化苯乙烯制苯甲醛,苯乙烯转化率达65.62%,苯甲醛的选择性81.21%,且V/SBA-15具有较好的催化剂稳定性. 相似文献
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采用水热法直接合成表面含丙磺酸基和不同烷基(如甲基、辛基和十六烷基)的疏水性介孔分子筛固体酸SBA-15-SO3H。实验表明,固体酸的硫质量分数为3.53%~4.255%,酸含量为(0.84~1.08) mmol·g-1,相对润湿接触角θr(SBA-15-SO3H)<θr(CH3-SBA-15-SO3H)<θr(C8H17-SBA-15-SO3H)<θr(C16H33-SBA-15-SO3H)。催化剂对冰醋酸和正丁醇的酯化反应转化率可达75.5%,转化率随相对润湿角的增大而增大。 相似文献
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以介孔分子筛SBA-15为载体,负载KNO3后焙烧制得K2O/SBA-15固体碱催化剂,以合成丙烯酸正丁酯的酯交换反应为探针反应,在间歇式反应釜中对K2O/SBA-15催化剂进行催化活性评价。结果表明,当K2O负载量为2%,K2O/SBA-15催化剂对此酯交换反应的催化活性最高。 相似文献
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采用溶胶-凝胶法制备了TiO2-Al2O3复合载体, 以柠檬酸为络合剂, 浸渍法制备了负载型Ni2P/TiO2-Al2O3催化剂前体, 程序升温H2还原法制备了Ni2P/TiO2-Al2O3催化剂, 并用 X 射线衍射(XRD)、N2吸附比表面积(BET)测定技术对催化剂的结构和性质进行了表征, 考察了浸渍方法、Ni/P摩尔比、Ni2P负载量对其进行的二苯并噻吩(DBT)加氢脱硫(HDS)性能的影响。结果表明, 当Ni/P比低于1:1时, 能得到单一的Ni2P物相;当Ni/P比为2:1时, 开始出现Ni3P物相。采用Ni/P比为1:1、Ni2P负载量为30%、采用共浸渍方法制备的Ni2P/TiO2-Al2O3催化剂具有最好的活性, 在360℃、3.0MPa、氢油比500 (体积比)、液时体积空速2.0h-1的条件下反应4h时, 二苯并噻吩转化率为99.5%。 相似文献
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Ping-Yi Wu Sheng-Fu Ji Lin-Hua Hu Ji-Qin Zhu Cheng-Yue Li 《Journal of Porous Materials》2008,15(2):181-187
A series of Mo2C/SBA-15 catalysts with different Mo contents were prepared by temperature-programmed carburization (TPC). The materials obtained
and their oxide precursors (MoO3/SBA-15) were characterized by Nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), and Fourier transform-infrared
(FT-IR) spectroscopy. The activities of the catalysts for deep hydrodesulfurization (HDS) of thiophene were evaluated. The
results of N2 adsorption-desorption isotherms indicated that the surface area and pore diameter of the oxide precursors increase after
carburization. The XRD patterns show that Mo2C particles are highly dispersed in the SBA-15 ordered mesoporous. The test results show that Mo2C/SBA-15 catalysts have an excellent performance for the deep HDS under the lower temperature region. 相似文献