KBrH2O2催化顺酐异构化合成富马酸

以KBr-H2O2为催化剂，在H2SO4存在下，顺酐异构化为富马酸。反应的最优条件为：顺酐15g，水30mL，H2SO4（8／5）1mL,KBr0.1g,H2O20.3mL，回流反应60min，产率达93％以上。     

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%.     

以稀土固体超强酸Gd3+-SO2-4/ZrO2催化合成三氯水杨酸正戊酯

以不同配比的Gd3+-SO2-4/ZrO2稀土固体超强酸合成三氯水杨酸正戊酯为探针反应,筛选出制备稀土固体超强酸Gd3+-SO2-4/ZrO2的最佳工艺条件为:20 g ZrOCl2·8H2O、1.0 %(质量分数)Gd2(SO4)3和0.8 mol·L-1H2SO4混合液,搅拌60 min后浸泡3 h,600 ℃焙烧3 h.以GSZ-1合成三氯水杨酸正戊酯的最佳反应条件为:72.8 g (0.3 mol) 3,5,6-三氯水杨酸、17.6 g (0.2 mol) 正戊醇、40 mL二甲苯和1.5 g的催化剂,电热套加热(105～110 ℃)回流反应2 h,酯化率可达93 %.     

Ce(SO4)2·2H2O催化合成丙二酸二丁酯

研究了以Ce(SO4)2·2H2O作催化剂,丙二酸和正丁醇为原料合成丙二酸二丁酯,结果表明醇酸比为2.51,催化剂用量为1.0g,带水剂环己烷为30mL,反应时间为2h是最适宜的反应条件,酯化率可达97.3%.     

稀土铈盐Ce(SO4)2·4H2O/NH2SO3H催化合成柠檬酸三丁酯

研究了柠檬酸与正丁醇在Ce(SO4)2·4H2O/NH2SO3H复配催化剂催化作用下制备柠檬酸三丁酯的工艺条件。实验结果表明Ce(SO4)2·4H2O/NH2SO3H催化合成柠檬酸三丁酯的最佳反应条件为:醇酸摩尔比为4.0∶1,催化剂用量为1.5%(以柠檬酸质量计),m[Ce(SO4)2·4H2O]∶m(NH2SO3H)=2∶1,反应温度为150℃,反应时间为7h,酯化率>98.5%,精制后产品纯度>99.5%。     

固体超强酸SO2-4/Fe2O3-CoO催化合成己酸乙酯

以固体超强酸SO2-4/Fe2O3-CoO为催化剂,通过己酸和乙醇反应合成了己酸乙酯.实验结果表明,固体超强酸SO2-4/Fe2O3-CoO对酯化具有较高的催化活性,反应的最佳条件为:己酸0.2mol,n(乙醇):n(己酸)=1.8:1.0,催化剂用量为0.8g(以0.2mol己酸为准),带水剂用量为12mL,反应时间为2h,其酯化率可达97%以上.     

固体超强酸SO2-4/SnO2-CeO2-高岭土催化合成乳酸丁酯

以质量比为1∶9∶20的硝酸铈铵、高岭土和SnCl45H2O制备了固体超强酸催化剂SO2-4/SnO2-CeO2-高岭土,制备条件为促进剂H2SO4浓度2.0 mol/L,浸渍12 h,350 ℃焙烧3 h,并采用Hammett指示剂法和XRD对其进行了酸强度和表面性能表征.该催化剂用于乳酸与正丁醇的酯化反应合成乳酸丁酯,结果表明,适宜反应条件为醇酸物质的量比1.8∶1、催化剂用量为反应物总质量的3.0%、甲苯10 mL,反应时间3.0 h,酯收率93.8%.催化剂重复使用4次酯收率仍可达80.8%.     

BiVO4催化剂的制备及其光催化还原CO2的研究

采用化学沉淀法制备BiVO4光催化剂并应用于光催化还原CO2/H2O体系中。通过TG-DTA、FTIR、XRD对光催化剂进行表征,研究了pH和焙烧温度等对光催化性能的影响。结果表明,pH=7并于600℃煅烧制得的单斜相BiVO4活性最高。在催化剂用量为0.6 g/L,反应时间为7 h,CO2流量为200 mL/min,反应温度为80℃,反应液中NaOH和Na2SO3的浓度均为0.10 mol/L条件下,甲醇产率高达249.18μmol/g。并对BiVO4催化剂光催化还原CO2的机理进行了探究。     

以稀土固体超强酸Gd^3＋-SO4^2-／ZrO2催化合成三氯水杨酸正戊酯

以不同配比的Gd3 -SO42-/ZrO2稀土固体超强酸合成三氯水杨酸正戊酯为探针反应,筛选出制备稀土固体超强酸Gd3 -SO42-/ZrO2的最佳工艺条件为:20 g ZrOCl2.8H2O1、.0%(质量分数)Gd2(SO4)3和0.8 mol.L-1H2SO4混合液,搅拌60 min后浸泡3 h,600℃焙烧3 h。以GSZ-1合成三氯水杨酸正戊酯的最佳反应条件为:72.8 g(0.3 mol)3,5,6-三氯水杨酸、17.6 g(0.2 mol)正戊醇、40 mL二甲苯和1.5 g的催化剂,电热套加热(105~110℃)回流反应2 h,酯化率可达93%。     

高纯V2O5制备钒电池用VOSO4的工艺研究

对以高纯V2O5为原料、SO2还原V2O5法制备VOSO4的工艺及其反应机理进行了研究,计算了制备VOSO4的反应焓变和吉布斯自由能变化,并用制备的VOSO4作为钒电池的活性材料进行了充放电性能测试。结果表明:该法生产工艺简单,V2O5∶SO2∶H2SO4的最佳摩尔比为1∶1.10~1.15∶1.10~1.15。制备出的VOSO4中V4+的含量占总钒量的99.71%、V5+含量仅占0.29%,具有良好的充放电性能,可以作为钒电池电解液的活性材料。     

Crystallization of zeolite L from Na2O-K2O-Al2O3-SiO2-H2O system

Zeolite L powder was prepared from the substrate mixture of Na₂O-K₂O-Al₂O₃-SiO₂-H₂O system at temperatures of 373-443 K. In order to investigate the factors which influence the synthesis outcome, a reference system which yields zeolite L in a reproducible manner was chosen and subjected to controlled changes in synthesis parameters. The crystalline zeolite L samples obtained were characterized by elemental chemical analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). It was established that phase purity, morphology, and the size of crystals of crystalline product were affected by molar ratios of the substrate, such as SiO₂/Al₂O₃, (K₂O+Na₂O)/SiO₂, Na₂O/(K₂O+Na₂O), and H₂O/(K₂O+Na₂O). Amorphous silica powder (Zeosil) was the preferred silica source, and the crystallization rate was promoted by introducing gel aging, seeding, and rapid heating rate.     

Photocatalytic activity of Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions

Cu₂O/TiO₂, Bi₂O₃/TiO₂ and ZnMn₂O₄/TiO₂ heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu₂O, Bi₂O₃ and ZnMn₂O₄ are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu₂O/TiO₂ and Bi₂O₃/TiO₂ by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed.     

碳酸钠—过氧化氢—水体系相图的绘制

进行了Na2CO3-H2O2-H2O体系溶解度的测定并绘制成相图,最后对其应用进行了讨论。     

Synthesis and characterization of Y2O3-ZrO2 and Y2O3-CeO2-ZrO2 precursor powders

Thixotropic gels of the precursor powders of the titled compounds have been prepared by the addition of oxalic acid to the mixed solutions of metal salts at room temperature (≈ 27 °C). The clear sols of yttrium-zirconyl oxalate (YZO) and yttrium-cerium-zirconyl oxalate (YCZO) gelled within a few hours and were oven-dried at 40 °C. The various stages of gelation behaviour of the sols are explained on the basis of DLVO theory. By repeptizing the dried gel powders with water, concentrated sols were prepared. The gelation time as a function of chloride ion concentration is discussed for both sols. The nature of the temperature dependence of the dried gel powders was studied by means of thermogravimetric analysis and differential thermal analysis. Powder X-ray diffraction was used to study the crystallization behaviour of the dried amorphous gel powders. It is found that these powders crystallize in tetragonal phase when calcined at 850 °C for 1 h. Estimation of surface area and infra-red characterization have also been carried out for the prepared powders.     

Preparation and characterization of Cr2O3-TiO2-Al2O3-V2O5 green pigment

Green pigments with high near infrared reflectance based on a Cr₂O₃-TiO₂-Al₂O₃-V₂O₅ composition have been synthesized. Cr₂O₃ was used as the host component and mixtures of TiO₂, Al₂O₃ and V₂O₅ were used as the guest components. TiO₂, Al₂O₃, and V₂O₅ were mixed into 39 different compositions. The spectral reflectance and the distribution of pigment powder were determined using a spectrophotometer and a scanning electron microscope, respectively. It was found that a pigment powder sample S9 with a Cr₂O₃-TiO₂-Al₂O₃-V₂O₅ composition of 80, 4, 14 and 2 wt%, respectively, gives a maximum near infrared solar reflectance of 82.8% compared with 49.0% for pure Cr₂O₃. The dispersion of pigment powders in a ceramic glaze was also studied. The results show that the pigment powder sample S9 is suitable for use as a coating material for ceramic-based roofs.     

Al2O3-SiO2-TiO2一ZrO2复合陶瓷膜的制备与表征

采用Sol—Gel法制备出掺杂SiO2，TiO2及ZrO2改性的γ-Al2O3膜，并通过SEM，EPMA，AFM等测试手段对膜结构和性能进行表征。探讨了制膜工艺条件对膜性能及结构的影响。制备的Al2O3复合膜膜厚为1—2μm，结构均匀无缺陷。     

Crystal Structure of the LiNaZnP2O7 Compound in the Li2ZnP2O7-Na2ZnP2O7 Glass-Forming System

The crystal structure of the LiNaZnP₂O₇ compound is determined using X-ray powder diffraction (space group Cmcm, a = 12.431 Å, b = 7.589 Å, c = 6.283 Å). The structure has a mixed tetrahedral framework consisting of the diortho groups [P₂O₇] and the tetrahedra [ZnO₄] and [LiO₄], which are joined into chains. The [ZnO₄] and [LiO₄] tetrahedra are distributed in the chains in a random manner, because the zinc and lithium atoms statistically occupy one crystallographic position. The sodium cations are arranged in channels of the tetrahedral framework. The atomic coordinates and interatomic distances in the structure are reported. Original Russian Text Copyright ? 2005 by Fizika i Khimiya Stekla, Shepelev, Lapshin, Petrova, Novikova.     

Investigation of the crystallization of zeolites in the SiO2-Al2O3-Na2O-K2O-(TEA)2O-H2O system

The crystallization of zeolites in the SiO₂-Al₂O₃-Na₂O-K₂O-(TEA)₂O-H₂O system, where (TEA)₂O is tetraethylammonium oxide, has been investigated over a wide range of variations in the SiO₂: Al₂O₃ ratio (from 5 to 19). It has been found that, in the composition region under investigation, zeolites crystallize with structures of paulingite, beta, phillipsite, merlinoite, erionite, mordenite, and garronite. The formation of the aforementioned phases is determined by the composition of the initial gels and the synthesis temperature. The cocrystallization of paulingite, phillipsite, and merlinoite is explained by the structural features of these zeolites.     

Stable Ti/RuO2-Sb2O5-SnO2 electrodes for O2 evolution

RuO₂-based electrodes are generally known to be unstable for O₂ evolution. In this paper, a stable type of RuO₂-based electrode, Ti/RuO₂-Sb₂O₅-SnO₂, is demonstrated for O₂ evolution. In the ternary oxide coating, RuO₂ serves as the catalyst, SnO₂ as the dispersing agent, and Sb₂O₅ as the dopant. The accelerated life test showed that the Ti/RuO₂-Sb₂O₅-SnO₂ electrode containing 12.2 molar percent of RuO₂ nominally in the coating had a service life of 307 h in 3 M H₂SO₄ solution under a current density of 0.5 A cm⁻² at 25 °C, which is more than 15 times longer than other types of RuO₂-based electrodes. Instrumental analysis indicated that RuO₂-Sb₂O₅-SnO₂ was a solid solution with a compact structure, which contributed to the stable nature of the electrode.