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1.
高佳  宋夫交  程文强  葛艳  许琦 《应用化学》2020,37(2):160-167
采用溶胶-凝胶法制备了n(Cu):n(Zr)=1:1、1:2、1:4和1:8的Cu/ZrO2催化剂。 实验结果表明,当n(Cu):n(Zr)=1:4时,催化剂表现出较高的CO2转化率(8.0%)和甲醇选择性(59.5%),为了增加CO2的转化率,提高甲醇选择性,在n(Cu):n(Zr)=1:4的催化剂中添加质量分数1%的Pd,采用浸渍法制备了Pd-Cu/ZrO2催化剂。 在250 ℃、2 MPa、12000 mL/(g·h)和V(H2):V(CO2)=3:1的反应条件下,CO2转化率和CH3OH收率相比Cu/ZrO2催化剂(n(Cu):n(Zr)=1:4)分别提高了40.0%和80.9%。 通过X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、N2吸附-脱附(BET)、X射线光电子能谱仪(XPS)和程序升温还原化学吸附仪(H2-TPR)等仪器表征证明Pd的添加提高了催化剂的分散性和比表面积。 催化剂中Pd和Cu之间强相互作用,使Cu2p轨道结合能向低处偏移,还原温度的降低,说明Pd-Cu/ZrO2催化剂还原能力增强,使得CO2加氢活性提高。  相似文献   

2.
张予东  高芸  张磊  李庆华 《应用化学》2019,36(5):539-547
通过差示扫描量热仪(DSC)和X射线粉末衍射仪(XRD)研究了聚-4-乙基苯酚抗氧剂对聚丙烯结晶行为的影响。 分别用Jeziorny法和Mo法处理非等温结晶动力学。 同时用Friedman法和Kissinger法计算其结晶活化能。 最后由结晶活化能与结晶温度的变化曲线求得Hoffman-Lauritzen参数成核速率常数(Kg)和迁移活化能(U*)值,进而求得折叠链端表面自由能(σe)和分子链段折叠功(q)。 结果表明,抗氧剂的加入,使聚丙烯的结晶峰温度向低温区移动,结晶半峰宽变大,半结晶时间(t1/2)增大,Jeziorny法所得的结晶速率常数(Z)降低,Mo法所得反映结晶速率快慢的参数F(T)提高,在相同结晶转化率下,结晶活化能负值变小。 Hoffman-Lauritzen参数KgU*σeq值均增大。 所有变化均表明聚-4-乙基苯酚抗氧剂对PP的结晶有抑制作用。  相似文献   

3.
相博文  王璐  王丰  王吉德 《应用化学》2018,35(12):1449-1456
采用等体积浸渍法制备了以分子筛为载体的铜基无汞催化剂(Cu/HY),在固定床反应器中,考察了Cu/HY催化剂用于乙炔氢氯化反应制取氯乙烯的催化性能,并采用扫描电子显微镜(SEM)、能量散射光谱(EDS)、电感耦合等离子光谱(ICP-AES)、氮气吸脱附(BET)、热重分析(TG)、透射电子显微镜(TEM)、X射线粉末衍射(XRD)和X射线光电子能谱(XPS)表征手段对反应前后的催化剂进行了表征和分析。 结果表明,反应温度为160 ℃,常压,空速为120 h-1,V(HCl)/V(C2H2)=1.25,Cu的负载质量分数为15%时,Cu/HY催化剂的乙炔氢氯化性能最佳,乙炔转化率可达84%,氯乙烯选择性始终大于95%,且具有较好的稳定性;通过表征分析,认为催化剂表面形成积碳,铜活性物种的还原、团聚和流失是导致Cu/HY催化剂活性下降的主要原因。  相似文献   

4.
有机-无机杂多酸类离子液体催化汽油超声氧化脱硫   总被引:2,自引:0,他引:2  
合成了一系列有机-无机杂多酸类离子液体, 并将其应用于超声作用下的催化模拟汽油氧化脱硫反应. 结果表明, 在超声波辅助下, 不仅反应时间大大缩短, 而且脱硫效率也大幅提高. 在合成的一系列催化剂中, Zr0.25[BMIM]HPW12O40表现出最佳的催化活性. 考察了超声波功率、 超声/间隙时间、 催化剂用量、 H2O2用量、 反应温度及反应时间等因素对脱硫效果的影响. 以Zr0.25[BMIM]HPW12O40为催化剂, 在优化的条件下[n(Cat.)=0.008 mmol, V(H2O2)=40 μL, V(模拟油)=10 mL, V(乙腈)=1 mL, 温度25 ℃, 时间10 min, 超声功率300 W, 超声时间2 s, 间隙时间1.5 s], 二苯并噻吩(DBT)的脱硫率达到97.8%; 该催化剂循环使用5次后, 脱硫率仍为81.9%; 其对不同硫化物的催化活性顺序为DBT>4,6-二甲基苯并噻吩(4,6-DMDBT)>乙硫醚>苯硫醚>正丁硫醇>甲基苯基硫醚>苯并噻吩(BT)>噻吩.  相似文献   

5.
利用单晶X射线衍射解析了[Co(aipamp)(amp)Cl][ZnCl4] (aipamp=2-[(2-氨基异丙基)氨基甲基]呲啶,amp=2-(氨基甲基)吡啶)体系中两个异构体Ⅱ的结构和[Co(apamp)(amp)Cl][ZnCl4](apamp=2-[(2-氨基丙基)氨基甲基]呲啶)体系中一异构体Ⅲ的结构.晶体Ⅰ属单斜晶系,空间群P21/n,a=1.08028(10) nm,b=1.84843(18) nm,c=1.25582(12) nm,α=90.00°,β=97.150(2)°,γ=90.00°,V=2.4881(4) nm3,Dc=1.620 g·cm-3,Z=6,F(000)=582,R=0.0361,wR=0.0974,晶胞中含4个配合物阳离子,4个[ZnCl4]2-阴离子;晶体Ⅱ 属三斜晶系,空间群 P1,a=0.9957(2) nm,b=1.0207(3) nm,c=1.1478(3) nm,α= 102.584(5)°,β=91.559(5)°,γ=98.462(5)°,V=1.1240(5) nm3,Dc=1.699 g·cm-3,Z=2,F(000)=580.00,R=0.0449,wR=0.0984,晶胞中含2个配合物阳离子,2个[ZnCl4]2-阴离子.晶体Ⅲ属三斜晶系,空间群P1,a=0.82423(7) nm,b=1.7199(8) nm,c=1.36399(1) nm,α=86.6350(10)°,β=81.7140(10)°,γ=67.6230(10)°,V=1.10278(15) nm3,Dc=1.734 g·cm-3,Z=2,F(000)=582.00,R=0.0332,wR=0.0823,晶胞中含4个配合物阳离子,4个[ZnCl4]2-阴离子.三异构体中Co3+为六配位,且配合物阳离子中具有C-H…π 结构.用一、二维核磁共振技术解析了第四个配合物在溶液中的结构,论证了该异构体属于[Co(apamp)(amp)Cl][ZnCl4]体系.4个异构体具有共同的结构特征--分子内C-H…π结构.  相似文献   

6.
以1.0代(G)超支化大分子(C38H51N9O2)为配体骨架,2-氯-4-甲基吡啶和CrCl3(THF)3为原料,依次经过取代和配合反应合成了一种超支化双吡啶亚胺配体及其铬催化剂。 利用紫外-可见光谱(UV-Vis)、傅里叶变换红外光谱(FT-IR)、电喷雾电离质谱(ESI-MS)、核磁共振氢谱(1H NMR)和元素分析等方法对其进行表征。 结果与理论设计预期一致。 考察了反应温度、乙烯压力、Al与Cr摩尔比(n(Al)/n(Cr))、溶剂及助催化剂种类等因素对催化剂催化乙烯齐聚性能的影响。 结果表明,以甲苯为溶剂,甲基铝氧烷(MAO)为助催化剂,当反应温度为45 ℃,乙烯压力为4 MPa,n(Al)/n(Cr)=300,催化剂用量为7 μmol时,活性可达1.32×105 g/(mol(Cr)·h),C6和C8的选择性为59.30%。  相似文献   

7.
三环己基氢氧化锡与L-扁桃酸(物质的量比1:1)在苯和乙醇混合溶剂中反应合成了三环己基锡L-扁桃酸酯。 经X射线衍射方法测定了其晶体结构,配合物属斜方晶系,空间群为P212121,晶体学参数a=0.80825(4) nm,b=1.77151(8) nm,c=1.8385(2) nm,α=β=γ=90°,V=2.6324(2) nm3,Z=4,Dc=1.310 g/nm3,μ(Mo)=9.92 cm-1,F(000)=1080,R1=0.0472,wR2=0.1341。 中心锡原子与环己基碳原子和氧原子构成畸型四面体。 对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及一些前沿分子轨道的组成特征。 研究了配合物的热稳定性、电化学性能、圆二色谱和体外抗癌活性。  相似文献   

8.
制备了2-氯甲基苯并咪唑硝酸盐(C8H8N2Cl+·NO3-)化合物,采用元素分析,IR, 1H NMR和TG-DTA对产物进行了表征,并采用X射线单晶衍射仪测定了该化合物的晶体结构,该化合物属单斜晶系,空间群P21/n, a=0.74189(3) nm, b=1.53064(6) nm, c=1.05478(3) nm, β=120.930(2)º, V=1.02744 nm3, Dc=1.484 g/cm3, Z=4, F(000)=472, μ=0.363 mm-1, R=0.0659, wR=0.1498, GOF=0.840.在此基础上,采用量子化学方法,在MP2/6-311G**, B3LYP/6-311G**和HF/6-311G**水平上计算了2-氯甲基苯并咪唑及其质子化阳离子的优化构型、电荷分布、振动光谱、热力学函数及总能量.计算结果显示2-氯甲基苯并咪唑环具有较强质子化能力,这与晶体结构结果相一致.  相似文献   

9.
以CeCl3·7H2O、CaCl2·2H2O和C2H2O4·2H2O为原料,在制备钙铈氧化物前驱体基础上,再以Ar气为载气、CS2为硫源对钙铈氧化物前驱体进行硫化合成Ca2+掺杂的γ-Ce2S3色料。 通过X射线衍射(XRD)、紫外-可见漫反射光谱(UV-Vis)及差热-热重分析(TG-DTA)等技术手段表征了色料的结构和性能。 结果表明,Ca2+掺杂能够明显降低γ-Ce2S3的合成温度,当n(Ca2+):n(Ce3+)≥0.16时,在900 ℃硫化150 min即可获得纯相的γ-Ce2S3,与不掺杂时合成γ-Ce2S3的温度相比降低了300 ℃左右。 同时,Ca2+掺杂能够提升γ-Ce2S3的抗氧化能力,当n(Ca2+):n(Ce3+)=0.64时,氧化放热峰的温度由不掺杂时的490.6 ℃提高至541.0 ℃。  相似文献   

10.
超微孔材料具有1~2 nm的孔径,在分离、催化应用中有望展现出择形催化的能力。 寻找经济、简便的合成超微孔材料的表面活性剂体系是一项有意义的工作。 本研究以短链季铵盐(十烷基三甲基溴化铵,记为C10TAB)和不同链长脂肪酸酸盐混合胶束为模板剂,硅酸钠为硅源,成功制备出高度有序超微孔SiO2。 通过小角X射线衍射、N2吸附-脱附、傅里叶变换红外光谱、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等技术手段对产品的结构和性能进行了表征。 结果表明,合成体系中脂肪酸盐碳链长、加入量、晶化温度等对产物孔道有序性有很大影响。 当选择正辛酸钠(SO)为助表面活性剂,当n(C10TAB):n(Na2SiO3):n(SO):n(H2O)=1:1.5:0.3:800,晶化温度为80 ℃时,可以得到高度有序超微孔SiO2。 煅烧后样品比表面积为1300 m2/g,孔体积0.49 cm3/g,孔径分布在1.90 nm。  相似文献   

11.
A new family of heteropolytungstate complexes (NH4)21[Ln(H2O)5{Ni(H2O)}2As4W40O140xH2O(Ln=Y, Ce, Pr, Nd, Sm, Eu, Gd) were prepared by the reaction of Na27[NaAs4W40O140]·60H2O with NiCl2·6H2O and Ln(NO3)3·xH2O at pH≈4.5. The crystal structures of (NH4)21[Gd(H2O)5{Ni(H2O)}2As4W40O140]·51H2O was determined by X-ray diffraction analysis and element analysis. The compound crystallizes in the monoclinic space group P21/n with a=19.754(3), b=24.298(4), c=39.350(6) Å, β=100.612(3)°, V=18564(5) Å3, Z=2, R1(wR2)=0.0544(0.0691). The central site S1 and two opposite sites S2 of the big cyclic ligand [As4W40O140]28− are occupied by one Ln3+and two Ni2+, respectively, each site supply four Od coordinating to metal ion, another one water molecule and other five water molecules coordinate, respectively, to Ni2+and Ln3+. Polyanion [Ln(H2O)5{Ni(H2O)}2As4W40O140]21− has C2v symmetry. IR and UV–vis spectra of [NaAs4W40O140]27− of the title compounds are discussed.  相似文献   

12.
Nickel(II) complexes of the tripodal ligand (MPz3tren) of the general formula [Ni(MPz3tren)]X2·nH2O (X=Cl, Br, NO3, ClO4 and BF4; n=0 for Cl and Br; n=0.5 for NO3, ClO4 and BF4) have been prepared by template methodology and characterised by elemental analyses, magnetic susceptibility and conductivity measurements at RT, IR and electronic spectra. The molar conductivities measured in MeOH for all the complexes show them to be 1:2 electrolytes. The hexadentate character of the ligand in all the complexes is inferred from IR spectral studies. The electronic spectra in solid state and in MeOH solution suggest octahedral geometry for all the complexes. The structure of [Ni(MPz3tren)](BF4)2·0.5H2O has been determined by single-crystal X-ray diffraction studies (monoclinic, c2/c). Nickel(II) is in a trigonal antiprismatic N6 donor environment and the crystal structure is stabilised by a network of strong H-bonding.  相似文献   

13.
在水热体系中合成了3个中心金属为镍离子, 以六配位扭曲八面体构型形成的具有螺旋结构的配位聚合物{[Ni2L2(bib)2·2H2O]·5H2O}n(1), [Ni2L2(bpy)]n(2)和{[Ni2L2(bibpip)2·2H2O]·6H2O}n(3)[H2L=4,4'-三苯胺二甲酸; bib=1,3-二(咪唑基)苯; bpy=4,4-联吡啶; bibpip=1,4-二(4-咪唑苄基)哌嗪]. 通过单晶及粉末X射线衍射、 红外光谱、 元素分析和热重分析对这3种化合物进行了表征. 结果表明, 化合物1属于单斜晶系, C2/c空间群, 其骨架为具有{42·65·8}拓扑结构的二维层结构; 化合物2属于斜方晶系, Fdd2空间群, 其骨架为具有{48·54·63}拓扑结构的三维超分子网络; 化合物3属于三斜晶系, P1ˉ空间群, 为1个五重穿插的三维超分子网络, 其骨架具有{44·62}拓扑结构.  相似文献   

14.
The structures of two glycinohydroxamoto (GHA) complexes of Ni(II) and Co(III) have been determined by single-crystal X-ray diffraction methods. The crystals of Ni(GHA)2 are monoclinic with a = 5.360(1), b = 7.315(4), c = 10.194(4) Å, β = 96.57(3), Z = 2, and space group P21/c. The crystals of Co(GHA)3•1/2 H2O are monoclinic with a = 22.467(19), b = 8.041(4), c = 13.700(11) Å, β = 116.01(7), Z = 8, and space group C2/c. The values of the final residuals R for Ni(GHA)2 and Co(GHA)3•1/2 H2O are 0.0275 and 0.032, respectvely. The molecular structures of Ni(GHA)2 and Co(GHA)3 consist of a square planar and an octahedral coordination, respectively, with the glycinohydroxamato (NH2CH2CONOH) ligands coordinating to the metal ion via the N (amino) and the N (NOH). These two complexes are the first well-established cases of coordination of the NHO group of a hydroxamic acid to a transition metal via the nitrogen atom.  相似文献   

15.
A series of novel heterobimetallic crown ether-like polyoxadiphosphaplatinaferrocenophanes cis-[1,1′-Fc(CH2O(CH2CH2O)nCH2CH2PPh2)2]PtCl2 (n=1–3) (4a–c) was synthesized in good yield by cyclization of the bis(phosphine) ligands 1,1′-Fc(CH2O(CH2CH2O)nCH2CH2PPh2)2 (n=1–3) (3a–c) and (PhCN)2PtCl2 under high dilution conditions in CH2Cl2. The bisphosphines 3a–c are obtained by reaction of the corresponding diols 1,1′-Fc(CH2O(CH2CH2O)nCH2CH2OH)2 (n=1–3) (1a–c) with: (i) CH3SO2Cl in CH2Cl2 and (ii) LiPPh2 in THF. Although the X-ray crystal structure of 4a shows that the cavity is large enough for the encapsulation of small metal cations, inclusion experiments of 4a–c with Group 1 cations, and Mg2+, or NH4+ in solution applying NMR titration and cyclovoltammetric methods reveal no evidence for the formation of host–guest complexes for 4a,b. In the case of 4c only the addition of Na+ or K+ leads to an insignificant effect.  相似文献   

16.
This work presents chemical modeling of solubilities of metal sulfates in aqueous solutions of sulfuric acid at high temperatures. Calculations were compared with experimental solubility measurements of hematite (Fe2O3) in aqueous ternary and quaternary systems of H2SO4, MgSO4 and Al2(SO4)3 at high temperatures. A hybrid model of ion-association and electrolyte non-random two liquid (ENRTL) theory was employed to fit solubility data in three ternary systems H2SO4–MgSO4–H2O, H2SO4–Al2(SO4)3–H2O at 235–270 °C and H2SO4–Fe2(SO4)3–H2O at 150–270 °C. Employing the Aspen Plus™ property program, the electrolyte NRTL local composition model was used for calculating activity coefficients of the ions Al3+, Mg2+ Fe3+ and SO42−, HSO4, OH, H3O+, respectively, as well as molecular species. The solid phases were hydronium alunite (H3O)Al3(SO4)2(OH)6, hematite Fe2O3 and magnesium sulfate monohydrate (MgSO4)·H2O which were employed as constraint precipitation solids in calculating the metal sulfate solubilities. A correlation for the equilibrium constants of the association reactions of complex species versus temperature was implemented. Based on the maximum-likelihood principle, the binary interaction energy parameters for the ionic species as well as the coefficients for equilibrium constants of the reactions were obtained simultaneously using the solubility data of the ternary systems. Following that, the solubilities of metal sulfates in the quaternary systems H2SO4–Fe2(SO4)3–MgSO4–H2O, H2SO4–Fe2(SO4)3–Al2(SO4)3–H2O at 250 °C and H2SO4–Al2(SO4)3–MgSO4–H2O at 230–270 °C were predicted. The calculated results were in excellent agreement with the experimental data.  相似文献   

17.
对七水合三氯化铈-碘化钠(CeCl3·7H2O-NaI)化邻氨基苯硫酚、 对氯邻氨基苯硫酚、 间氨基苯硫酚、 对氨基苯硫酚和对甲基苯硫酚与α,β-不饱和酮(1a~1o)的迈克尔加成反应进行了系统研究. 结果表明, CeCl3·7H2O-NaI-SiO2复合催化剂能有效催化邻氨基苯硫酚及对氯邻氨基苯硫酚与α,β-不饱和酮(1a~1o)的迈克尔加成反应. 在优化的反应条件下, 即n(CeCl3·7H2O):n(NaI):n(α,β-不饱和酮)=1:2:2, m(CeCl3·7H2O):m(SiO2)=1:1.6, 三氯甲烷作溶剂, 反应温度为回流温度, 反应时间为2 h, 反应可达到中等产率(43.1%~58.8%). 催化剂重复使用4次基本稳定. 此外, 提出了可能的催化机理.  相似文献   

18.
Reactions of CoX2·6H2O (X = Cl, ClO4) with bis(3,5-dimethylpyrazolyl)methane (dmpzm) and formic acid, acetic acid, benzoic acid, salicylic acid, maleic acid, or fumaric acid under the presence of KOH solution produced a new family of Co(II)/dmpzm complexes, [Co(dmpzm)2L]X·nH2O (1: L = O2CH, X = Cl, n = 2; 2: L = OAc, X = Cl, n = 3; 3: L = benzoate, X = ClO4, n = 1/3; 4: L = salicylate, X = ClO4, n = 1/3) and [Co2(dmpzm)4L](ClO4)2·nSolv (5: L = maleate, n = 3, Solv = H2O; 6: L = fumarate, n = 2, Solv = MeOH). These compounds were structurally characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1–4 are mononuclear while 5–6 are binuclear. Each cobalt atom of 1–6 is hexacoordinate, with a distorted octahedral CoN4O2 coordination geometry incorporating two N,N′-bidentate dmpzm ligands and one O,O′-bidentate carboxylate ligand. There are rich intra- and intermolecular hydrogen bonds in the crystals of 1–6, thereby forming either 2D hydrogen-bonded networks (1 and 2) or 3D hydrogen-bonded networks (3–6). In addition, the thermal behaviors of 1–6 were also investigated.  相似文献   

19.
《Polyhedron》2000,19(28):2689-2695
The reaction of an ethanolic solution of copper(II) pyridinecarboxylates CuX2·nH2O (where X is nicotinate (nic) (n=0) or isonicotinate (isonic) (n=4)) with ethylenediamine (en) in a molar ratio of 1:2 lead to the isolation of solid tetragonally distorted octahedral complexes of the type [Cu(en)2(H2O)2]X2·nH2O (n=1 for nic; n=0 for isonic). The analogous reaction of CuX2·nH2O with diethylenetriamine (dien) in a molar ratio of 1:1 leads to the formation of square-pyramidal pentacoordinated complexes of the type [CuX(dien)(H2O)]X. On the other hand, the reaction of equimolar quantities of copper(II) nitrate and dien with nicotinate anions (equimolar quantities of pyridinecarboxylic acid and NaOH) in ethanolic solutions gives a solid monomeric complex [Cu(nic)(NO3)dien)(H2O)]·H2O in which the coordination polyhedron around the Cu(II) atom is a (4+1+1) distorted tetragonal bipyramid. Based on the molecular structure the electronic and IR spectra are discussed. Moreover, the results of the quantitative determination of antimicrobial activity of the isonic complexes [Cu(isonic)2(H2O)4], [Cu(en)2(H2O)2](isonic)2, [Cu(isonic)(dien)(H2O)](isonic), as well as isonicotinic acid, ethylenediamine and diethylenetriamine alone are discussed.  相似文献   

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