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The [PdCl2(NH2(CH2)12CH3)2] complex supported on -Al2O3 has proved to be a considerably more active, selective and sulfur-resistant catalyst in the selective hydrogenation of styrene to ethylbenzene than a traditional catalyst obtained from acid solutions of PdCl2, and even than the same complex unsupported. The active species is the complex itself and it is stable under the reaction conditions. Hydrogen treatments above 353K destroy the complex, at least partially, leading to a less active and sulfur resistant catalyst. The higher sulfur resistance, when compared to a conventional Pd/Al2O3 catalyst, can be attributed to electronic and geometrical effects. 相似文献
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(C4H9NH3)2(CH3NH3)Pb2I7是一种Ruddlesden-Popper相钙钛矿材料,具有层状结构,层间通过van der Waals力结合,因此可以通过机械剥离的方法,获得其二维薄层。二维(C4H9NH3)2(CH3NH3)Pb2I7内束缚激子会自发复合从而表现出强的荧光,其圆极化率、峰位均受磁场调控。在外磁场中,荧光圆极化率与磁场呈线性关系,激子中电子和空穴之间的朗德因子差Δg约为0.43。束缚激子在磁场中受抗磁效应影响,致使其发光峰随磁场增加而红移。 相似文献
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Lenka Klištincová Erik Rakovský Peter Schwendt Gustav Plesch R. Gyepes 《Inorganic chemistry communications》2010,13(11):1275-1277
The decavanadate with a novel glycine–glycinato complex of copper (II) in the cationic part, (NH4)2[Cu2(H2O)4(NH3CH2COO)2(NH2CH2COO)2]H2V10O28·6H2O (1), has been prepared and characterized by elemental analysis, infrared and EPR spectroscopies. The triplet X band EPR spectrum of powdered sample evidenced magnetic interaction between the Cu(II) atoms in the dimeric unit which is probably realized through the bridging water molecules in this part of the complex. A single crystal X-ray diffraction study revealed that the structure of 1 contains cationic copper complex with a rare Cu(H2O)2Cu double bridge. In this cation, a simultaneous bidentate N, O– and monodentate O– coordination of glycine to the same central atom was observed for the first time. 相似文献
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《Inorganic chemistry communications》2003,6(8):1099-1103
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采取水热法成功合成MIL-53(Cr)晶体,分别应用0.1、1、3 mol·L-1的氨气对MIL-53(Cr)进行改性,制得系列的NH3@MIL-53(Cr)-1#,NH3@MIL-53(Cr)-2#,NH3@MIL-53(Cr)-3#。实验结果表明:与原始的MIL-53(Cr)晶体相比,尽管制得NH3@MIL-53(Cr)系列材料的比表面积依次减少,但其单位比表面积的CO2吸附容量大小依次为:NH3@MIL-53(Cr)-3#>NH3@MIL-53(Cr)-2#>NH3@MIL-53(Cr)-1#。表明氨气改性会使得材料表面的碱性增强,从而增强了其对酸性气体CO2的吸附。此外,改性后的NH3@MIL-53(Cr)对水蒸气的吸附量明显减少,表明其憎水性能得到改善。较高浓度氨气改性会导致材料的比表面积大幅下降,会引起单位质量吸附剂的吸附容量下降。用1 mol·L-1浓度的氨气改性得到的NH3@MIL-53(Cr)-2#,不仅对CO2的吸附容量最大,而且对CH4的吸附容量明显下降,这将有助于进一步提高改性材料NH3@MIL-53(Cr)-2# 对CO2/CH4的吸附选择性。 相似文献
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利用无溶剂加热方法,以N,N-二甲基乙醇胺(DMEA)和七甲基三硅氧烷(MDHM)为原料,合成Me3SiOMeRSiMe3〔R=O(CH2)2N(CH3)2〕。讨论了反应中反应时间,反应温度,反应物摩尔比,催化剂浓度等因素对反应转化率的影响。采用正交实验,对以无溶剂加热法合成MDHM型三硅氧烷叔胺的工艺进行优化,并利用减压蒸馏分离提纯和气相色谱技术确定纯后产物纯度,并且经过质谱分析和核磁共振鉴定产物的结构。 相似文献
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采用Gaussian 98从头算程序包,从理论上对乙腈与氯原子的夺氢反应的动力学进行了研究。在UB3LYP/6—311G(d,p)水平下优化了反应物、产物和过渡态的几何结构,用UMP4(SITFQ)方法进行了单点能校正,并计算出它们的谐振频率和反应在温度区问250~750K的速率常数。 相似文献
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本研究测定了30℃时KNO3和NH4NO3在0 ̄30%(Wt)NH3的水溶液中的共饱和度,并通过分析NH3含量对KNH3及NH4NO3共饱和度的影响,得出了以NH3为盐析剂,从KNO3和NH4NO3的混合水溶液中晶析KNO3的规律,为KNO3和NH4NO3的分离提供理论依据。 相似文献
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采用共沉淀法制备了WO3/TiO2-ZrO2脱硝催化剂,并用固定床反应器进行活性评价,采用BET、XRD、TPD、氨气吸附漫反射FT-IR进行表征。结果显示,ZrO2掺杂增强了TiO2的Lewis酸性;负载WO3之后,位于3.1~1.7 nm之间孔隙的稳定性显著增强;NH3的吸附与活化分别由TiO2-ZrO2载体和WO3完成;WO3中W元素强大的电负性,促进了NH3的N-H键由共价键向离子键过渡,进而导致了NH3的活化。脱硝活性结果显示:当WO3含量为9%(质量)时,催化剂脱硝活性最高,并在320~420℃的温度窗口保持94%以上。(9%)WO3/TiO2-ZrO2具有更加稳定的孔隙结构(4.4~1.7 nm),表面Brønsted酸中心数量增加,Lewis酸中心的强度和酸量增加的幅度最大,NH3-SCR过程中的活性中间产物NH2的吸收峰更加明显,这些特征可能是其脱硝活性最好的原因。 相似文献
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由SO2,NH3和NaCl制无水亚硫酸钠 总被引:3,自引:0,他引:3
由SO_2、NH_3和NaCl制无水亚硫酸钠卢芳仪,周建始,邱祖民(南昌大学)无水亚硫酸钠主要用于织物漂白、染料中间体、照相显影、造纸、人造纤维、皮革、医药合成、硫代硫酸盐制造等,是较为重要的无机盐。传统的生产方法是用纯碱吸收SO。,制得含Na。SO。... 相似文献
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本文介绍利用NH_3—SO_2—SO_3—H_2O水盐体系各主要相图对氨法处理硫酸尾气的实际操作进行各种近似的运算。例如,求取饱和吸收液的结晶率,选取合理的工艺条件等。 相似文献
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分别利用MP2/6-31+G(d)和B3LYP/6-311++G(d,P)上对NH4+NHi(H2O)2和NH4+(H2O),进行结构计算.最终得到了8种NH4NH3(H2O)2的稳定构型,6种NH4+(H2O),的稳定结构.发现NH4+NH2(H2O)2结构仅是NH3分子替代了NH4+(H2O),的一个H2O分子.N... 相似文献
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Shengyan Meng Liang Wu Miao Liu Zhaolun Cui Qian Chen Shangkun Li Jiahui Yan Li Wang Xinkui Wang Ji Qian Hongchen Guo Jinhai Niu Annemie Bogaerts Yanhui Yi 《American Institute of Chemical Engineers》2023,69(10):e18154
We report a plasma-assisted CO2 hydrogenation to CH3OH over Fe2O3/γ-Al2O3 catalysts, achieving 12% CO2 conversion and 58% CH3OH selectivity at a temperature of nearly 80°C atm pressure. We investigated the effect of various supports and loadings of the Fe-based catalysts, as well as optimized reaction conditions. We characterized catalysts by X-ray powder diffraction (XRD), hydrogen temperature programmed reduction (H2-TPR), CO2 and CO temperature programmed desorption (CO2/CO-TPD), high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM), x-ray photoelectron spectroscopy (XPS), Mössbauer, and Fourier transform infrared ( FTIR). The XPS results show that the enhanced CO2 conversion and CH3OH selectivity are attributed to the chemisorbed oxygen species on Fe2O3/γ-Al2O3. Furthermore, the diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) and TPD results illustrate that the catalysts with stronger CO2 adsorption capacity exhibit a higher reaction performance. In situ DRIFTS gain insight into the specific reaction pathways in the CO2/H2 plasma. This study reveals the role of chemisorbed oxygen species as a key intermediate, and inspires to design highly efficient catalysts and expand the catalytic systems for CO2 hydrogenation to CH3OH. 相似文献
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由理论推导出尿素冷凝液中NH3 和CO2 的分析方法 ,用标准溶液实验 ,检验方法的正确性。并推导出NH3·H2 O、NH4 HCO3、(NH4 ) 2 CO3 的摩尔电导计算公式 ,运用公式计算出混合溶液的电导率与实测电导率之间的误差 ,揭示混合溶液中电导率、电离度与各物质浓度的关系 相似文献
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Mn-Fe-Ce/TiO2低温NH3选择性催化还原NO 总被引:1,自引:0,他引:1
采用浸渍法制备了MnO2-Fe2O3-CeO2/TiO2催化剂用于低温NH3选择性催化还原烟气中NO,考察了Mn, Fe, Ce含量及焙烧温度对NH3选择性催化还原NO的活性和抗水性能的影响. 在气体体积空速(GHSV)=24000 h-1, NH3/NO=0.8(j), 350℃煅烧和烟气含3%(j) O2的条件下,该系列催化剂的脱硝活性为MnO2-Fe2O3-CeO2/TiO2>MnO2- Fe2O3/TiO2>MnO2/TiO2,且在200℃时MnO2(10)-Fe2O3(5)-CeO2(5)/TiO2的脱硝率为95%. 对含10%(j)水蒸汽的烟气,MnO2(10)-Fe2O3(5)-CeO2(5)/TiO2的脱硝活性维持在87%;在10%(j)水蒸汽和100′10-6 SO2共存条件下,短时间内脱硝活性维持在55%. 相似文献