稀土固体超强酸SO_4~(2-)/TiO_2/Ce~(4 )催化剂的制备及性能研究

用溶胶-凝胶法制备了稀土固体超强酸催化剂SO42-/TiO2/Ce4 ,用于催化苯甲醛与乙二醇的缩合反应。考察了硫酸的浓度、Ce(SO4)2的浓度和焙烧温度等因素对催化性能的影响;采用IR、DSC、XRD和Hammett指示剂法对其性能进行研究。结果表明,催化剂SO42-/TiO2/Ce4 是合成苯甲醛乙二醇缩醛的良好催化剂,在硫酸浓度1 mol.L-1、Ce(SO4)2的浓度0.12 mol.L-1和焙烧温度550℃的制备条件下,产率可达88.2%。催化剂晶体结构为锐钛矿型。     

稀土固体超强酸SO2^-4/TiO2/Ce^4＋催化剂的制备及性能研究

采用溶胶-凝胶法制备了稀土固体超强酸催化剂SO2-4/TiO2/Ce4+,用于催化苯甲醛与乙二醇的缩合反应.考察了硫酸的浓度、Ce(SO4)2的浓度、焙烧温度等因素对其催化性能的影响,并采用IR、DSC、XRD等对其性能进行了研究.实验表明,在硫酸浓度为1mol·L-1、Ce(SO4)2的浓度为0.12mol·L-1、催化剂焙烧温度为550℃的制备条件下,苯甲醛乙二醇缩醛产率可达89.5%,此时催化剂晶体结构为锐钛矿型.     

稀土固体超强酸SO_4~(2-)/TiO_2/Ce~(4+)催化剂的制备及性能研究

采用溶胶-凝胶法制备了稀土固体超强酸催化剂SO42-/TiO2/Ce4+,用于催化苯甲醛与乙二醇的缩合反应。考察了硫酸的浓度、Ce(SO4)2的浓度、焙烧温度等因素对其催化性能的影响,并采用IR、DSC、XRD等对其性能进行了研究。实验表明,在硫酸浓度为1mol·L-1、Ce(SO4)2的浓度为0·12mol·L-1、催化剂焙烧温度为550℃的制备条件下,苯甲醛乙二醇缩醛产率可达89·5%,此时催化剂晶体结构为锐钛矿型。     

稀土固体超强酸SO42－/TiO2/Ce4+催化剂的制备及性能研究

用溶胶-凝胶法制备了稀土固体超强酸催化剂SO₄^2－/TiO₂/Ce⁴⁺，用于催化苯甲醛与乙二醇的缩合反应。考察了硫酸的浓度、Ce(SO₄)₂的浓度和焙烧温度等因素对催化性能的影响；采用IR、DSC、XRD和Hammett指示剂法对其性能进行研究。结果表明，催化剂SO₄^2－/TiO₂/Ce⁴⁺是合成苯甲醛乙二醇缩醛的良好催化剂，在硫酸浓度1 mol·L^－1、Ce(SO₄)₂的浓度012 mol·L^－1和焙烧温度550 ℃的制备条件下,产率可达88.2％。催化剂晶体结构为锐钛矿型。     

SO2-4/γ-Al2O3催化合成苯甲醛缩乙二醇

以SO2-4/γ-Al2O3为催化剂,以苯甲醛和乙二醇为原料进行缩合反应合成了苯甲醛缩乙二醇.考察了催化剂的制备条件如硫酸浸渍浓度、焙烧温度对催化活性的影响;同时也考察了反应条件如反应物摩尔比、催化剂用量、反应时间对苯甲醛转化率的影响.结果表明,SO2-4/γ-Al2O3是合成苯甲醛缩乙二醇的良好催化剂.催化剂的最佳制备条件为:硫酸浸渍浓度2.5 mol·L-1,焙烧温度650℃;最佳反应条件为:苯甲醛0.05 mol,n(苯甲醛):n(乙二醇)=1:2,催化剂1.0 g,带水剂环己烷5 mL,100℃回流反应120 min.此时苯甲醛转化率可达96.51%.催化剂可回收利用,回收效率取决于焙烧温度.     

SO4^2-/γ-Al2O3催化合成苯甲醛缩乙二醇

以SO42-/γ-Al2O3为催化剂,以苯甲醛和乙二醇为原料进行缩合反应合成了苯甲醛缩乙二醇。考察了催化剂的制备条件如硫酸浸渍浓度、焙烧温度对催化活性的影响;同时也考察了反应条件如反应物摩尔比、催化剂用量、反应时间对苯甲醛转化率的影响。结果表明,SO42-/γ-Al2O3是合成苯甲醛缩乙二醇的良好催化剂。催化剂的最佳制备条件为：硫酸浸渍浓度2.5 mol.L-1,焙烧温度650℃;最佳反应条件为：苯甲醛0.05 mol,n（苯甲醛）∶n（乙二醇）=1∶2,催化剂1.0 g,带水剂环己烷5 mL,100℃回流反应120 min。此时苯甲醛转化率可达96.51%。催化剂可回收利用,回收效率取决于焙烧温度。     

SO2-4/TiO2光催化降解邻硝基苯酚

采用硫酸溶液浸渍处理TiO2制得SO2-4/TiO2光催化剂.考察了光催化剂对邻硝基苯酚溶液的光催化行为.发现SO2-4/TiO2的光催化活性高于TiO2,浸渍液中H2SO4的浓度和催化剂的焙烧温度对SO2-4/TiO2的催化活性有一定的影响,H2SO4溶液的最佳浓度为0.5 mol·L-1,最佳焙烧温度为500℃.催化降解过程符合一级反应动力学规律.     

SO_4~(2-)/γ-Al_2O_3催化合成苯甲醛缩乙二醇

以SO42-/γ-Al2O3为催化剂,以苯甲醛和乙二醇为原料进行缩合反应合成了苯甲醛缩乙二醇。考察了催化剂的制备条件如硫酸浸渍浓度、焙烧温度对催化活性的影响;同时也考察了反应条件如反应物摩尔比、催化剂用量、反应时间对苯甲醛转化率的影响。结果表明,SO42-/γ-Al2O3是合成苯甲醛缩乙二醇的良好催化剂。催化剂的最佳制备条件为:硫酸浸渍浓度2.5 mol.L-1,焙烧温度650℃;最佳反应条件为:苯甲醛0.05 mol,n(苯甲醛)∶n(乙二醇)=1∶2,催化剂1.0 g,带水剂环己烷5 mL,100℃回流反应120 min。此时苯甲醛转化率可达96.51%。催化剂可回收利用,回收效率取决于焙烧温度。     

Fe3+、Ce4+掺杂改性对SO2-4/TiO2固体超强酸催化尿囊素催化性能的研究

采用液相浸渍的方法对SO2+4/TiO2进行Fe、Ce双元素掺杂改性,以合成尿囊素产率大小为判断标准,考察通过掺杂改性后的催化剂催化性能,优化制备催化剂的工艺条件.结果表明,当Ce4+:TiO2=0.06%、Fe3+:TiO2=0.2%,浸渍溶液是硫酸,浸渍浓度为0.66mol·L-1,浸渍溶液的体积为15 mL/g,浸渍时间为20 h,焙烧温度540℃,焙烧时间3.4h,尿囊素的产率最高,催化活性最佳,可重复使用4次以上,重复实验得到的尿囊素平均产率基本维持在65%左右.制得的尿囊素进行产品鉴定,符合工业标准.     

SO_4~(2-)/TiO_2光催化降解邻硝基苯酚(英文)

采用硫酸溶液浸渍处理TiO2制得SO42-/TiO2光催化剂。考察了光催化剂对邻硝基苯酚溶液的光催化行为。发现SO42-/TiO2的光催化活性高于TiO2,浸渍液中H2SO4的浓度和催化剂的焙烧温度对SO42-/TiO2的催化活性有一定的影响,H2SO4溶液的最佳浓度为0.5 mol.L-1,最佳焙烧温度为500℃。催化降解过程符合一级反应动力学规律。     

Low-temperature catalytic combustion on Pt/SO 4 2− /ZrO2 and Pd/SO 4 2− /ZrO2 catalysts

Low-temperature combustion of various organic compounds on Pt/SO ₄ ^–2 /ZrO₂ and Pd/SO ₄ ^–2 /ZrO₂ was studied. For these organic compounds, especially saturated hydrocarbons, the combustion activities of Pt/SO ₄ ^–2 /ZrO₂ are higher than those of Pt/ Al₂O₃. Pt/SO ₄ ^–2 /ZrO₂ combustion catalysts can be used in a wide range of space velocity and oxygen content. The catalytic activity is enhanced with an increase of Pt loading from 0.1 to 1.0 wt%. The superacidity of the support material is responsible for the improvement in activity rather than an increase in catalyst surface area or metal dispersion. Pd/SO ₄ ^–2 /ZrO₂ are less active than Pt/SO ₄ ^–2 /ZrO₂.     

Boosting selective C2H2/CH4, C2H4/CH4 and CO2/CH4 adsorption performance via 1,2,3-triazole functionalized triazine-based porous organic polymers

Nitrogen-rich porous organic polymers have shown great potentials in gas adsorption/separation, photocatalysis, electrochemistry, sensing and so on. Herein, 1,2,3-triazole functionalized triazine-based porous organic polymers (TT-POPs) have been synthesized by the copper-catalyzed azide-alkyne cycloaddition (Cu-AAC) polymerization reactions of 1,3,5-tris(4-azidophenyl)-triazine with 1,4-diacetylene benzene and 1,3,5-triacetylenebenzene, respectively. The characterizations of N₂ adsorption at 77 K show TT-POPs possess permanent porosity with BET surface areas of 666 m²·g^-1 (TT-POP-1) and 406 m²·g^-1 (TT-POP-2). The adsorption capacities of TT-POPs for CO₂, CH₄, C₂H₂ and C₂H₄, as well as the selective separation abilities of CO₂/N₂, CO₂/CH₄, C₂H₂/CH₄ and C₂H₄/CH₄ were evaluated. The gas selective separation ratio of TT-POPs was calculated by the ideal adsorbed solution theory (IAST) method, wherein the selective separation ratios of C₂H₂/CH₄ and C₂H₄/CH₄ of TT-POP-2 was 48.4 and 13.6 (298 K, 0.1 MPa), which is comparable to other adsorbents (5.6-120.6 for C₂H₂/CH₄, 10-26 for C₂H₄/CH₄). This work shows that the 1,2,3-triazole functionalized triazine-based porous organic polymer has a good application prospect in natural gas purification.     

Solid Solubility and Polymorphism in the System Sr2SiO4-Sr2GeO4-Ba2GeO4-Ba2SiO4

The reciprocal salt pair Sr₂SiO₄-Sr₂GeO₄-Ba₂GeO₄-Ba₂SiO₄ was investigated using X-ray powder diffraction and DTA. Unlimited solubility in the low-K₂SO₄ structure type (α') occurs throughout the system above 85°C. The nonlinear changes of some lattice constants of the solid solutions are discussed. A stable monoclinic low-temperature (β) form of Sr₂SiO₄ was found which converts reversibly to the high-temperature α'-modification at 85°C. The enthalpy of the β-α' transition is 51 cal/mol. In the reciprocal salt pair the β-form solid solutions occur in a very narrow region below 85°C.     

ZIF-8/乙二醇-水浆液吸收-吸附CH4/H2和CH4/N2

为了有效地捕集焦炉气及煤层气中的甲烷,提出了一种新型捕集技术:吸收-吸附组合方法,该方法通过把ZIF-8分散到乙二醇水溶液中形成悬浮浆液,实现对甲烷组分的捕集。首先测定了甲烷、氮气和氢气在浆液中的吸收-吸附容量,得出吸着量大小的顺序为CH₄> N₂> H₂,然后对CH₄/H₂和CH₄/N₂的混合气进行吸着平衡研究,发现浆液均能有选择性地吸着甲烷。对浆液中回收的ZIF-8材料进行XRD表征,分析证明在整个吸着过程中ZIF-8结构没有发生变化并且ZIF-8/乙二醇-水浆液能重复利用。     

N2H4/H2O2/CuSO4常压催化氢化SB

首次以水合肼和双氧水的氧化还原反应对两嵌段共聚物SB进行选择性加氢，并着重考察了各种氢化条件对加氢反应的影响，加氢度达到95％。本方法既具有学术上的理论意义，又对光纤材料国产化有重要意义。     

The Series MgCr2O4-MgFe2O4

The characteristics of spinels in the series MgCr₂O₄-MgFe₂O₄ were determined. The plot of cell size vs. molar composition is unusual in series showing complete solid solution because an unusually large deviation from Vegard's law was observed. This deviation is caused by changes in spinel structure with composition and temperature, and an equation was derived which applies a correction in terms of the degree of inversion. The effects of temperature on compositions high in MgFe₂O₄ include changes in density and refractive index. Solid solution of forsterite in MgCr₂O₄ decreases the cell size to 8.329 A but apparently is less than 1%. Changes in composition caused by vapor loss or by dissociation are small enough that this series is essentially binary below 1400° C.     

The System K2SO4-Cs2SO4

The phase diagram for the system K₂SO₄-Cs₂SO₄ was determined by using DTA for melting relations and DTA and high-temperature X-ray diffractometry for subsolidus relations. At the solidus the system shows complete solid solubility, with a minimum at 940°C and 50 mol% Cs₂SO₄. Orthorhombic K₂SO₄ and Cs₂SO₄, the stable low-temperature forms, show mutual solid solubility and form a eutectoid at 50 mol% Cs₂SO₄ and 430°C, the lowest temperature of stability of the high-temperature hexagonal solid-solution phase. Isothermal plots of the a and c dimensions of this hexagonal phase vs composition show large positive deviations from linearity for c. These deviations are interpreted on the basis of the crystal structure of KNaSO₄ with a similar unit cell.     

WO3-TiO2-SO42-固体超强酸的制备及应用研究

TiO2·nH2O和H2WO4混合,其中w(H2WO4)=10%,然后用c(H2SO4)=1 mol/L的溶液浸渍,在600 ℃焙烧3 h,可制得Ho≤-14.52的WO3-TiO2-SO42-固体超强酸.其w(SO3)=4.7%,总酸量为0.85 mmol/g,比表面积为110 m2/g.用其催化乙酸丁酯液相酯化反应,乙酸转化率可达96%.     

磁性固体超强酸ZrO2／SO4^2—催化合成乙酸正己酯

制备了磁性固体超强酸催化剂，并用于乙酸和正己醇的酯化反应，对反应的工艺条件进行了优化。结果表明：乙酸用量为0．1mol时，醇酸摩尔比为1．8，催化剂用量为1．5g，15ml苯作带水剂，反应时间为1．5h，其酯化率可达89％以上，同时利用催化剂的磁性可将催化剂迅速分离。     

CO2/CH4 and CH4/N2 separation on isomeric metal organic frameworks☆

Two isomeric metal-organic frameworks(MOFs) with 2-dimensional(2D) and 3-dimensional(3D) topologies both comprised of Cu(Ⅱ) and OTf(OTf = trifluoromethanesulfonate) ions were synthesized and characterized.The CO_2,CH_4 and N_2 adsorption properties of the two isomeric MOFs were investigated from 263 K to 298 K at0.1 MPa.The results showed that the 2D MOF exhibited a higher selectivity for CO_2 from CO_2/CH_4 and CH_4from CH_4/N_2 compared to the 3D MOF,even though it possessed a lower surface area and pore volume.The higher adsorption heats of gases on the 2D MOF inferred the strong adsorption potential energy in the layered MOFs.Dynamic separation experiments using CO_2/CH_4 and CH_4/N_2 mixtures on the two MOFs proved that the2 D MOF had a longer elution time than the 3D MOF as well as better separation abilities.