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1.
对合成功能材料磷酸镧的新方法进行了研究,以聚乙二醇-400 (PEG-400)为表面活性剂,LaNO38226;6H2O和(NH4)3PO48226;3H2O为原料,用低热固相反应法成功合成得到磷酸镧。用产物XRD图谱数据计算得到的结晶度作为试验的考察指标,试验中应用了均匀设计试验法及数据挖掘技术,在数据挖掘成果的指导下进行了试验。试验结果表明,用最优工艺条件合成得到的产物为23nm的LaPO48729;0.5H2O,结晶度为97.8%与数据挖掘得到的最佳结果相吻合。TG/DTA分析结果表明LaPO48729;0.5H2O在300℃下加热脱水可以转变成为LaPO4。 相似文献
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酸性离子液体中苯甲醇催化氧化合成苯甲醛 总被引:2,自引:0,他引:2
在没有任何有机溶剂和卤素的条件下,以30%H2O2为氧化剂,Na2WO4·2H2O为催化剂,在酸性离子液体[(CH2)4SO3HMIm]TSO中,研究了苯甲醇选择性氧化合成苯甲醛。在n(苯甲醇)∶n(H2O2)∶n(离子液体)∶n(Na2WO4·2H2O)=40∶48∶1∶1、90 ℃和3 h条件下,催化效果最好,此时苯甲醇转化率为90.1%,苯甲醛选择性为92.1%。反应结束后,产物和离子液体分层,通过简单的倾倒即可分离产物。分离后的离子液体经真空干燥脱水后重复使用4次,催化活性基本不变。 相似文献
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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7 h,酯化率>98.5%,精制后产品纯度>99.5%。 相似文献
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本文报道用于甲基丙烯醛(MAL)选择氧化制甲基丙烯酸(MAA)的PMoV杂多酸盐催化剂的研究结果。IR和XRD考察结果表明,本文所研究的催化剂均具有稳定的Keggin结构,催化剂物相组成为H4-2y-zPO4(MO3)12-x(VO3)xCuyCsz。在300 ℃,原料气组成MAL:H2O:O2:N2=1:10:3:32,体积空速1 200 h-1的条件下,最佳催化剂的MAL转化率为94.1%,选择性达88.7%。 相似文献
6.
稀土双膦酸酯配合物和稀土氯化物对Mannich反应的催化作用 总被引:1,自引:1,他引:0
研究了Dy(OTf)3、DyCl3和稀土双膦酸酯配合物{ [Dy(OTf)2L2(H2O)2](OTf)(CH3CN)}[L=(iPrO)2P(O)CH2P(O)(iPrO)2] 等对Mannich 反应的催化作用,发现以Dy(OTf)3为催化剂时,收率为54%,[Dy(OTf)2L2(H2O)2](OTf)(CH3CN)的收率仅为8%,DyCl3收率达47%。研究了12种稀土金属氯化物对Mannich 反应的催化作用,其中,ErCl3催化剂的收率最高,达到61%。 相似文献
7.
烟气气相组分及Ca(OH)_2对KMnO_4氧化NO的影响机理 总被引:2,自引:1,他引:1
在固定床反应器中考察了KMnO4氧化烟气中NO的过程,分析了烟气组分H2O、O2及SO2对NO氧化过程的影响规律,得到了Ca(OH)2对KMnO4氧化NO的影响机理。实验结果表明,H2O是KMnO4氧化NO的必要条件;在含H2O条件下,O2可以提高NO氧化率。SO2与氧化剂反应生成无水钾镁钒类复盐K2Mn2(SO4)3对NO氧化具有负面作用;Ca(OH)2的加入提高了氧化剂表面的固体碱度从而促进氧化过程进行;通过添加Ca(OH)2可以降低SO2对NO氧化过程的负面影响。根据气体成分和产物分析可知,KMnO4在钙基吸收剂表面氧化烟气中NO的机理可能是KMnO4以离子态将吸附在氧化剂表面的NO和SO2氧化为NO2和SO3,生成的NO2、SO3再传递到氧化位临近的碱性位被吸收。 相似文献
8.
在固定床反应器中考察了KMnO4氧化烟气中NO的过程,分析了烟气组分H2O、O2及SO2对NO氧化过程的影响规律,得到了Ca(OH)2对KMnO4氧化NO的影响机理。实验结果表明,H2O是KMnO4氧化NO的必要条件;在含H2O条件下,O2可以提高NO氧化率。SO2与氧化剂反应生成无水钾镁钒类复盐K2Mn2(SO4)3对NO氧化具有负面作用;Ca(OH)2的加入提高了氧化剂表面的固体碱度从而促进氧化过程进行;通过添加Ca(OH)2可以降低SO2对NO氧化过程的负面影响。根据气体成分和产物分析可知,KMnO4在钙基吸收剂表面氧化烟气中NO的机理可能是KMnO4以离子态将吸附在氧化剂表面的NO和SO2氧化为NO2和SO3,生成的NO2、SO3再传递到氧化位临近的碱性位被吸收。 相似文献
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新型层状粘土结构F-T合成催化剂的研制 总被引:1,自引:0,他引:1
用FeCl3·6H2O和Na2SiO3水玻璃共沉淀法制备蒙脱土结构的新型F-T合成催化剂。用XRD、SEM和N2低温吸附-脱附等方法对催化剂的物相结构进行测定,确认催化剂具有层状结构并有较高的比表面积。催化剂经过预处理,F-T合成在浆态床反应器中进行,反应条件:270 ℃,0.5 MPa,气流量34.5 mL·min-1,n(H2)∶n(CO)=2∶1,反应时间6 h。产物分析得知,C9~C25烃类的选择性达到90%以上,使ASF分布规律发生正偏移。 相似文献
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采用金相、显微激光拉曼和X射线衍射等技术研究了仿古铸铁在模拟土壤介质(0.06 mol8226;L-1 NaCl+0.03 mol8226;L-1 Na2SO4+0.01 mol8226;L-1 NaHCO3溶液)中的腐蚀形态、腐蚀产物的形貌及其生长和发展过程.结果表明,在最初的34 h内,铸铁发生铁的选择性腐蚀,在试样表面留下许多白色圈状的Fe(OH)2沉淀,圈内则是分散状的Fe(OH)2;浸泡120 h时,观察到试样表面有一层深绿色的腐蚀产物,其组分主要为GR(Cl-)(化学式为FeⅡ3FeⅢ(OH)8Cl8226;2H2O)和GR(SO2-4)(化学式为FeⅡ4FeⅢ2(OH)12SO48226;2H2O),绿锈表面呈黄色;约288 h后,腐蚀产物呈现分层,内层主要由黑色结晶状的FeO和Fe3O4组成,外层主要为疏松多孔的砖红色γ-FeOOH,后者是铁器表面的一种有害锈. 相似文献
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Solubilities and properties (density, conductivity and pH value) of solutions in the quaternary system Li+,K+//CO2-3,B4O2-7-H2O at 288 K were experimentally studied with the isothermal equilibrium method. The phase diagram of the system consisted of two invariant points E and F, five univariant curves, and four crystallization fields that belonged to K2CO3·3/2H2O,Li2B4O7·3H2O,K2B4O7·4H2O and Li2CO3. The composition of the solution corresponding to E was w(CO2-3)=2.27 %,w(B4O2-7)=6.05 %,w(K+ )=4.30%,w(Li+)=0.30 % and the equilibrium solids were Li2B4O7· 3H2O+K 2B4O7·4H2O+Li2CO3;The composition of the solution for F was w(CO2-3)=22.45%,w(B4O2-7)=1.88%,w(K+ )=29.96%,w(Li+ )=0.03% and the equilibrium solids were K2CO3·3/2H2O+K 2B4O7·4H2O+Li2CO3. K2CO3 possesses strong salting-out effect on K2B4O7,Li2CO3 and Li2B4O7. 相似文献
12.
Rapid-setting magnesium monophosphate cementitious materials were prepared by mixing calcined magnesium oxide (MgO) powder with an aqueous solution of diammonium phosphate (ADP) at 24°C. The activation energy for the curing reaction of the cement paste was determined to be 30.29 kcal/mole, and at age 1 hr the compressive strength was ≈900 psi (6.2 MPa). X-ray diffraction studies of the cured cement indicated that the major reaction product was magnesium orthophosphate tetrahydrate [Mg3(PO4)2·4H2O]. Magnesium ammonium phosphate hexahydrate [MgNH4PO4·6H2O] and Mg(OH)2 were also detected. Subsequent heating of the cement to 1300°C resulted in the conversion of the three compounds to a single phase of anhydrous magnesium orthophosphate [Mg3(PO4)2]. The resultant product had a compressive strength of 7000 psi (48.23 MPa) and was thermally stable in air at temperatures >1000°C. 相似文献
13.
Fenton's reagent was employed in the decolorization of aqueous solutions of one of three dyestuffs (Acid Red 27, Reactive Blue 81, Acid Blue 62). The decolorization with Fenton's reagent was found to be simple and fast. In order to determine the reaction kinetics of the decolorization the stopped-flow technique under pseudo-first order conditions was used. Experiments were carried out at pH=2, at the excess of ferrous salts (FeCl2·4H2O or FeSO4·7H2O). The rate constants of the decolorization determined by us are in the same order of magnitude: 90 to 100 dm3/(mol-s) for FeSO4·7H2O/H2O2, and 40 to 50 dm3/(mol-s) for FeCl2·4H2O/H2O2 systems. The difference between the rate constants for both ferrous salts indicates that the Fenton's reaction may proceed via different mechanisms. 相似文献
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Three new beryllium phosphates, namely, H3aep·Be2(PO4)2(H2PO4)·H2O (1), H2tmdp·Be3(HPO4)3(PO4CH3)·2.25H2O (2), and H2dmpda·Be3(PO4)(HPO4)2(H2PO4) (3), were prepared under solvothermal conditions. These compounds display different open-framework structures with hcb (for 1), sql (for 2), and bnn (for 3) topologies, respectively. The formation of phosphate ester from in situ esterification reaction of phosphoric acid and methanol is noteworthy. 相似文献
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Bo Wei Duo Xu Zhan Yong Yang Fan Sun Xiao Qing Gu Chang Yu Sun Fang Yu Guo Qiao Yun Li Gao Wen Yang 《Journal of Inorganic and Organometallic Polymers and Materials》2017,27(1):131-142
Two inorganic mixtures of copper and sodium compounds have been synthesized and characterized with different measurement techniques. The thermal property of these mixtures has been studied to low temperature up to 223 from 573 K with DSC. The specific heat capacity of this mixture has been measured in atmospheric O2 at a rate of 10 K min?1 from 573 to 223 K and vice versa in two thermal cycles. The net specific heat capacity of these mixtures is found endothermic in first and second thermal cycles. The net specific heat capacity of 0.5Cu2(PO4)(OH); 3.5CuH(PO4)2·H2O; 2NaHSO4·H2O (CuPHS) during first thermal cycle is ?71203.05 J kg?1 K?1 and in second thermal cycle is ?73881.67 J kg?1 K?1 between temperature range of 303–223 K. The net specific heat capacity of mixture 0.5Cu2(PO4)(OH); 3.5CuH(PO4)2; 2Na2SO4(CuPS) in first thermal cycle is ?21158.37 J kg?1 K?1 and in second thermal cycle is?45739.92 J kg?1 K?1 between temperature range of 298–573 K. As both mixtures are endothermic in nature in all cycles, it can be used as heat storage material.The average crystallite size of mixture 0.5Cu2(PO4)(OH); 3.5CuH(PO4)2·H2O; 2NaHSO4·H2O and 0.5Cu2(PO4)(OH); 3.5CuH(PO4)2; 2Na2SO4 is ~47 and ~17.3 nm, respectively. 相似文献
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Responses of ZnSO4, Zn3 (PO4)2 · 4H2O, ZnO, ZnNH4PO3 · 2H2O and zincated superphosphate were studied on wheat (Triticum aestivum) and pearl-millet (Pennistem americanum) in Balsamand sand (Ustipsament) and Ladwa fine loam (Typic Camborthids). In Balsamand sand all Zn fertilizers increased wheat and pearl-milllet grain yield significantly over control but ZnNH4 PO4 · 2H2O and zincated super were the best sources. Straw yield was also highest due to zincated super and ZnNH4PO4 · 2H2O applications. Zinc sulphate was significantly inferior to zincated super and ZnNH4PO4 · 2H2O. In Ladwa fine loam, all fertilizers gave significantly higher grain yield of wheat and pearl-millet than control except ZnO in pearl-millet. Highest yield in this soil was obtained by ZnSO4 · 7H2O followed by ZnNH4 PO4 · 2H2O and then zincated super.In Balsamand sand, the Zn fertilizers significantly increased the Zn concentration and Zn uptake of wheat grain. In pearl-millet, only Zn uptake was increased significantly with Zn fertilizers. Zincated super gave highest Zn uptake.The concentration of P in wheat grain was increased by Zn fertilizers in Balsamand sand, and also in pearl-millet where zincated super and ZnNH4PO4 were most effective in increasing the P content.When Zn fertilizers were applied to preceding pearl-millet the effect on succeeding wheat crop were in the same order as direct application of Zn fertilizers. Zincated super was the best and ZnO worst with respect to wheat grain and straw yield and uptake of Zn and P. 相似文献
18.
Jens Christoffers 《Advanced Synthesis \u0026amp; Catalysis》1999,341(5):495-498
Dipeptides derived from methionine and S-methylcysteine 3a – d have been prepared and screened as chiral ligands in combination with 13 metal salts 4a – m towards the catalysis of an asymmetric Michael reaction of a β-keto ester 1 with methyl vinyl ketone 2 resulting in an optimal ee of 18% achieved with FeCl3 · 6 H2O 4c as the metal salt. 相似文献
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Studies on the formation and identification of the nature of reaction products formed with zinc and ortho- and pyrophosphate fertilizers were carried out in chemical solutions and in contrasting Indian soils having wide pH range from acidic to alkaline. Triammonium pyrophosphate (TPP), a constituent of the newly developed ammonium polyphosphate (APP) and diammonium orthophosphate (DAP), the only orthophosphate fertilizer manufactured and used in the country were taken for these studies. The reaction products (precipitates) formed in the solutions were isolated and identified through X-ray diffraction technique and chemical analysis, and those formed at the sites of fertilizer placement separated and identified only through X-ray diffraction technique. In the study with solutions ZnNH4PO4 (orthorhombic) was identified at all levels of Zn applications and at both concentrations of 0.1Mg and 1.0M DAP; whereas, Zn3(NH4)2(P2O7)2.2H2O was observed only at the lower concentration (0.1 M) of TPP with Zn. Zinc was completely soluble at the higher concentration (1.0M) of TPP indicating the formation of a soluble complex, (NH4)6Zn(P2O7)2.6H2O. In soils, the reaction products obtained with band application of DAP alone and along with Zn fertilizers were CaHPO4.2H2O, Ca(NH4)2(HPO4)2.H2O (dimorph B), MgNH4PO4.6H2O (struvite), MgHPO4.3H2O, FePO4.2H2O (metastrengite, monoclinic), AlPO4.2H2O (orthorhombic), ZnNH4PO4 (orthorhombic) and Zn3(PO4)2.4H2O. The reaction products with TPP alone and with Zn were Ca(NH4)2P2O7.H2O, Mg(NH4)2P2O7.4H2O (monoclinic), FeH2P2O7, Ca2P2O7.2H2O (monoclinic) and Zn(NH4)2P2O7.H2O. 相似文献