THE INFLUENCE OF PRETREATMENT ON REFORMING SELECTIVITY OVER Pt-Re-A1_2O_3 AND Pt-Ir-Al_2O_3 CATALYSTS

In n-C_7~(?)reforming catalysis the selectivity of Pt-Ir-Al_2O_3 catalystis superior to that of Pt-Re-Al_2O_3 catalyst n-C_7~(?) shows deeper cracking onPt-Re-Al_2O_3 catalysts.Different reduction methods influence the selectivityof Pt-Re-Al_2O_3 catalyst.but have less influence on Pt-Ir-Al_2O_3 catalyst Thecracking activity and cracking depth of Pt-Re-Al_2O_3 catalyst deerease withthe water content present in the reduction process.     

Mn_3O(Salea)_2(C_2H_3O_2)_3·HC_2H_3O_2的合成、表征及放氧活性测定

合成了三核锰(Ⅲ)Schiff碱配合物:Mn_3O(Salea)_2(C_2H_3O_2)_3·HC_2H_3O_2(其中Salea~(2-)为水杨醛缩乙醇胺Schiff碱阴离子),经元素分析、磁矩、化合价、电导率、热分析、红外、紫外光谱等进行表征,并利用氧电极进行了放氧活性测试,发现在对苯醌存在下配合物能促使水分解释放氧气,其反应受温度、对苯醌和配合物浓度等因素影响,并提出了可能的放氧反应方程.     

SYNTHESIS AND CRYSTAL STRUCTURE OF COMPLEX [CrMo_3 (μ_3-O)_3(μ-O)(μ-O_2CCH_3)_5(O_2CCH_3)_3]Na2 · H_2O

<正> The title complex C CrMo3 (μ3-O )3 (μ-O) (μ-O2CCH3 )5 (O2CCH3)3]2Na2 · H2O (Mr=1814. 32) crystallizes in monoclinic, space group P21/ n with a=11.209(5), b=18. 05(1), c=14. 44(1) A , β= 98. 30(5)°. V=2890 (3) A3, Z=2, A = 2. 08 g/cm3, F(000) -1780, Final R = 0. 049, Rw = 0. 058 for 2622 independent reflectons with I>3σ(I). The complex anion contains two Mo3O4 cores which connect two chromium atoms through four μ3-O atoms and eight bridging CH3COO- groups. Each of the Cr atoms and the Mo atoms is coordinated by six oxygen atoms. The anions are linked by Na cations to form one-dimensional infinite chain structure.     

SYNTHESIS AND CRYSTAL STRUCTURE OF A TRITUNGSTEN CLUS-TER COMPOUND [W_3O_2(O_2CCH_3)_6(H_2O)_3]ZnBr_4·8H_2O

<正> C12H40O25Br4W3Zn, Mr = 1520. 71, monoclinic, space group P1, a = 10. 470(4) b=17. 669(6),c=14. 477(2) A ,α=99. 80(2),αB=101. 51(2),γ=99. 78 (4)°,V=1829A3,Z = 2,DX = 2. 66g/cm3,λ(MoKa) = 0. 71073A,μU= 146. 9cm-1,F (000) = 1408. Final R=0. 038,Rw = 0. 049 for 4088 independent observable reflections.     

γ-A1_2O_3改性对AlCl_3/γ-Al_2O_3催化剂性能的影响（英文）

采用HCl和NaOH改性γ-A12O3载体制备AlCl3/γ-A12O3固载催化剂,用吡啶-FTIR和吡啶-TPD技术分析了催化剂的表面酸性(酸中心类型、酸强度和酸量),并以1-癸烯齐聚作为探针反应,研究了催化剂的稳定性以及催化剂对聚合反应的影响.结果表明,催化剂含有两种酸类型,即Lewis酸和Brnsted酸,与未改性的催化剂相比,氢氧化钠改性载体制备的催化剂,酸量增大了47%,催化剂催化1-癸烯的齐聚反应活性增加了11.4%;而经盐酸改性制备的催化剂酸量增大112%,催化剂的活性增加了33.6%.酸强度依AlC l3/γ-A12O3,AlC l3/γ-Al2O3(NaO H),AlC l3/γ-Al2O3(HCl)的顺序增强.     

［Vmo_3O_4（O_2CEt）_8］_2Na_2的合成与结构

［ＶＭｏ３Ｏ４（Ｏ２ＣＥｔ）８］２Ｎａ２（１），三斜晶系，Ｐ１空间群，ａ＝１２．９７７（７），ｂ＝１４．０７０（６），ｃ＝１２．３３８（８），α＝１０９．８１（４），β＝１１７．２０（４），γ＝９０．５１（５）°，Ｖ＝１８４８．８３，Ｍｒ＝２０２０．６，Ｄｃ＝１．８１ｇ／ｃｍ３，Ｚ＝１，Ｆ（０００），μ＝１２．９ｃｍ１（ＭｏＫα）对３７４２个可观测反射点（Ｉ＞３σ（Ｉ））最终一致性因子为Ｒ＝０．０１８，Ｒω＝０．０５４。单晶结构分析表明，簇阴离子中两个［Ｍｏ３Ｏ４］４＋单元通过两个＂桥＂金属Ｖ原子连接成一个奇特的环状结构，Ｍｏ－Ｍｏ平均键长为２．５１９（１），Ｍｏ…Ｖ间平均距离为３．６５４。簇阴离子通过Ｎａ＋连成一个一维长链，Ｎａ原子与氧原子形成一个少见的五配位三角双锥结构，Ｎａ－Ｏ距离仅为２．３１２，Ｎａ－Ｏ间较强的相互作用以及无限长链的晶体结构很好地解释了簇合物（１）的稳定性和不溶性。     

STRUCTURE OF TRISUBSTITUTED TUNGSTOSILICATE ANION [A-β-SiW_9Al_3(H_2O)_2O_36(μ_3-O2/2)]_2~14-

<正> Crystal of H14C[A-β-SiW9Al3(H2O)2O36(μ3-O2/2)]2 ·8H2O belongs to monoclinic system, space group P2/m. with a= 1 7. 525(6), b=14.348(3). c= 21. 669(8) A , β=113. 12(8)°, V = 5011 (3) A3,Z = 2. Dc = 3. 254 g. cm-3, A (MoKα) = 0. 70169 A , μ=223. 21 cm-1, F(000) = 4614, T = 298K. R=0. 066 for 3010 unique reflections [I≥5σ(I) ]. The crystal consists of water molecules, protons (or H3O+ ) and dimeric anions [A-β-SiW9Al3 (H2O)2O36(μ3-O2/2)D214.the half of which has a SiO1 tetrahedron in the center, a W3O13 group, two W2Al(H2O) O12 groups and a W2AlO13 group around the SiO4.     

{[(n-Bu)_2Sn(O_2CCH═CHAr)]_2O}_2的合成、表征和{[(n-Bu)_2Sn(O_2CCH═CHPh)]_2O}_2的晶体结构

利用 (n Bu) 2 SnO与ArCHCHCO2 H反应 ,合成 5个二聚二丁基锡芳基丙烯酸酯氧化物 {[(n Bu) 2 Sn(O2 CCHCHAr) ] 2 O}2 .通过元素分析、红外光谱和核磁共振氢谱对其结构进行了表征 .用X射线单晶衍射测定了 {[(n Bu) 2 Sn (O2 CCHCHPh) ] 2 O}2 ( 1)的晶体结构 ,结果表明 ,化合物 1是以Sn2 O2 四面体为中心的 ,中心对称的二聚体结构 ,内环锡为五配位的畸变三角双锥构型 ,外环锡为六配位的畸变加帽体三角双锥结构 .该化合物属三斜晶系 ,空间群P1- ,a =1 0 172( 11)nm ,b =1 3 80 4( 16)nm ,c =1 470 3 ( 17)nm ,α =10 6 75 0 ( 18)° ,β =10 5 61( 2 ) )° ,γ =10 0 2 95 ( 18)° ,Z =1,V =1 82 9( 4 )nm-3 ,Dc=1 413g/m3 ,μ =1 40 0mm-1 ,F( 0 0 0 ) =792 ,R =0 0 5 5 9,wR =0 12 5 0 .     

NiO-La_2O_3-Al_2O_3气凝胶催化剂的制备

采用改进的溶胶 -凝胶法和超临界干燥技术制备出超细三元 Ni O- L a2 O3 - Al2 O3 气凝胶催化剂 .通过 BET、TEM、XRD、DTA、IR等物性表征 ,考察了煅烧温度和组成等对气凝胶催化剂制备的影响 .结果表明 ,此种方法制备的多元气凝胶催化剂不仅保留了氧化铝和 Ni O- Al2 O3 气凝胶的主要特征 ,而且 ,氧化镧的加入使气凝胶更易晶化 ,热稳定性更好和吸附能力更强 .这种改进的溶胶 -凝胶法和超临界干燥技术操作简单有效 ,适合要求组分之间相互作用强、分布均匀、结构热稳定性好的多组元负载催化剂的制备 .     

Kinetics of the Oxidative Dehydrogenation of Isobutane over Cr_2O_3/La_2(CO_3)_3

The oxidative dehydrogenation (ODH) of isobutane over Cr2O3/La2(CO3)3 has been investigated in a low-pressure Knudsen cell reactor, under conditions where the kinetics of the primary reaction steps can be accurately determined. By heating the catalyst at a constant rate from 150-300℃, temperature fluctuations due to non-equilibrium adsorption are minimized. The evolved gas profiles show that ODH to isobutene and water is a primary reaction pathway, while carbon dioxide, which forms from the catalyst during reaction, is the only other product. This CO2 evolution may enhance the activity of the catalyst. Isobutene formation proceeds with the participation of lattice oxygen from the Cr2O3/La2(CO3)3 catalyst. The intrinsic Arrhenius rate constant for the ODH of isobutane isk(s-1) = 1011.5±2.2exp{-((55±5) -ΔHads kJmol-1)/RT}The small pre-exponential factor is expected for a concerted mechanism and for such a catalyst with a small surface area and limited porosity.     

CRYSTAL STRUCTURE OF Mo_3(μ3-S)_2(μ-Cl)_3[S_2P(OEt)_2]_3

<正> M=1013.98, hexagonal, P63/m, a=b=15.492(2), c=8.530(4)A, γ=120°, V=1773A3, Z=2, Dc=1.899°g.cm-3. Final R=0.042 for 611 reflections.This is a Bl(bicapped) type trinuclear molybdenum cluster with two S capping atoms located on the 63 axis and exhibits full D3h symmetry. The Mo-Mo distances are 2.606(1)A, with a bond order of 11/3. It is paramagnetic.     

SYNTHESIS AND CRYSTAL STRUCTURE OF A TRITUNGSTEN CLU-STER COMPOUND H[W_3O_2(O_2CCH_3)_9]·5H_2O

In this paper we report the structure of another new W3 cluster compound H[W3O2(O2CCH3)9]·5H2O prepared by the method reported previously. The title compound crystal lizes in monoctinic system, space group P21 with cell dimensions: a = 8. 237(3),6=13. 273(2),c=14.508(4)A,β=92.97°(3),V=1584A3.Z=2,and Dc=2. 529g/cm3.The average W - W, W -U_3-O,W -Oac and W -Ot distances are 2. 775, 2. 01,2. 09 and 2. 04 A, respectively.     

STUDY ON TETRANUCLEAR TRANSITION METAL CLUSTER WITH μ_3-O BRIDGES I . SYNTHESIS AND CRYSTAL STRUCTURE OF [Fe_4O_2(O_2CCH_3)_7(2,2''''-bipy)_2]Cl

INTRODUCTION.The first tetranuelear oxo一bridged manganese eomplex eon-taining〔Mn4OZ〕“+eore was reported on its synthesis,strueture and magnetie proper-ties in 1 987〔‘〕,representing the best available model for the photosynthetie water oxi-dation eentre.In order to find out the relationship of aetivity with eonfiguration ofthis kind of eomplexes,a series of dual oxo一bridged tetranuelear eomplexes have beensynthesized in our laboratory〔2〕.In this paper the aeetato一bridged tetran…     

A1_2O_3 Effect on the Catalytic Activity of Cu-ZnO-Al_2O_3-SiO_2 Catalysts for Dimethyl Ether Synthesis from CO_2 Hydrogenation

1. Introduction Dimethyl ether (DME) has received more and more attention as a clean alternative diesel fuel since it has higher cetane value, lower NOx emission, lesser carbon particulates and near-zero smoke compared with those for the traditional diesel fuels [1,2]. So far DME has been produced from methanol dehydra- tion over solid-acid catalysts [2,3] or from syngas over bifunctional catalysts [1,4-7]. Recently, great efforts have been emphasized on the direct synthesis of DME from C…     

Nb_2O_5/γ-A1_2O_3表面铌氧物种的分散状态与酸性特征

负载型Nb_2O_5是多种催化反应的有效催化剂.以草酸铌为前驱物,γ-Al_2O_3为载体,通过浸渍法制备不同负载量的Nb_O_5/γ-Al_2O_3催化剂.采用粉末X射线衍射(XRD)、激光拉曼光谱(LRS)和吡啶吸附傅立叶变换红外(Py-IR)光谱方法对催化剂表面铌氧(NbO_x)物种的分散特征、酸性特征进行表征,通过异丁烯(IB)与异丁醛(IBA)缩合生成2,5-二甲基-2,4-己二烯(DMHD)反应评价催化剂表面酸催化活性.结果表明,Nb在γ-Al_2O_3表面的单层分散容量(г_(Nb)为7.6 μmol·m~(-2),与"嵌入模型"理论分析:Nb~(5+)分散在γ-Al_2O_3优先暴露晶面(110)上八面体空位中的单层分散容量值7.5 μmol·m~(-2)接近,即分散的Nb~(5+)离子键合在γ-Al_2O_3表面八面体空位中.在低负载量下,分散在γ-Al_2O_3表面的Nb_2O_5主要以孤立的NbO_x物种形式通过Nb--O--Al键与载体表面键合,与LRS结果一致.处于孤立状态下的NbO_x物种使表面Lewis酸位量下降.随负载量的增加,孤立的NbO_x物种通过Nb--O--Nb键连接而聚集,并形成表面Br(o)nsted酸位,随着NbO_x聚集度增加,表面Br(o)nsted酸密度增加,酸性增强,对IBA与IB缩合反应催化活性增加.当负载量超过单层分散容量时,NbO_x物种呈现三维聚集状态,DMHD的转化频率(TOF)降低,同时表面Br(o)nsted酸性增强,导致目标产物DMHD的选择性降低.Nb2_O_5/γ-Al_2O_3催化剂表面Br(o)nsted酸特征与NbO_x物种聚集状态密切相关.     

A New Bis-(As_3O_6) Capping 6-Molybdonickelate Complex:Preparation and Characterization of [Ni(en)_2(H_2O)]_2[(NiO_6)Mo_6O_(18)(As_3O_3)_2]·2H_2O

A new complex constructed from a unit with two As3O6 rings capping Anderson-type moieties,[Ni(en)2(H2O)2]2[(NiO6)Mo6O18(As3O3)2]·2H2O(1,en = ethylenediamine),has been hydrothermally synthesized and characterized by IR,single-crystal X-ray diffraction and thermogra-vimetric analysis.The compound crystallizes in triclinic,space group P1 with a = 9.1230(16),b = 11.8078(9),c = 12.2111(9) ,α = 114.5210(10),β = 98.0350(10),γ = 100.0320(10)o,Mr = 2029.80,C8H44As6Mo6N8Ni3O36,V = 1145.0(2) 3,Dc = 2.944 g/cm3,Z = 1,GOF = 0.997,μ = 7.203 mm-1,F(000) = 970,R = 0.0352 and wR = 0.1019.Compound 1 consists of an Anderson-type capped by a two-ring(As3O6) unit [(NiO6)Mo6O18(As3O3)2]4-,two six-coordinate [Ni(en)2(H2O)2]2+ cations and two water molecules.     

A New Modification of Tellurite Phosphate: β-Te_3O_3(PO_4)_2

A new modification of tellurite phosphate, β-Te_3O_3(PO_4)_2, has been synthesized under hydrothermal conditions and its crystal structure was determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic space group P2_1/n(No. 14), with a = 11.115(5), b = 4.7033(19), c = 17.287(7) ?, β = 106.086(5)°, V = 868.3(6) ?~3, Z = 4, P_2 Te_3 O_(11), M_r = 620.74, D_c = 4.748 g/cm~3, μ(Mo Kα) = 10.438 mm~(–1) and F(000) = 1096. The final full-matrix least-squares refinement converged to R = 0.0227, wR = 0.0534 for 1984 observed reflections with I 2σ(I), and R = 0.0240, w R = 0.0540 for all data(2070) and S = 1.117. β-Te_3O_3(PO_4)_2 is polymorphic with the known α-Te_3O_3(PO_4)_2(Weil H. M. et al. Z. Anorg. Allg. Chem. 2003, 629, 1068-1072). The crystal structure of β-Te_3O_3(PO_4)_2 features a three-dimensional(3D) network composed of Te_6 O_(22)~(20)-hexanuclear clusters interconnected by PO_4 groups. Te_6 O_(22) hexanuclear cluster is built from three Te_2 O_8 dimers(edge-sharing TeO_5 square pyramids) linked to each via sharing O-corners. The structure difference between α-and β-forms of Te_3O_3(PO_4)_2 lies in the polymerization of tellurite oxides Te_nO_m. 1D infinite ~1_∞{[Te_3 O_(11)]~(10-)} single chains are presented in α-Te_3O_3(PO_4)_2, while 0D discrete Te_6 O_(22) hexanuclear clusters are observed for β-Te_3O_3(PO_4)_2. Moreover, thermal analyses, infrared spectra and UV-Vis-NIR diffuse reflectance are also presented.     

α-羟基乙酸氧钒钾K_2[VO(C_2H_3O_3)_2(C_2H2O_3)]·H_2O的晶体和分子结构

VOSO_4与α-羟基乙酸在水溶液中进行反应,用KOH调节到适当的pH值,制得兰绿色的晶体化合物.晶体属单斜晶系,空间群为P2_1/b.在CAD4 四圆衍射仪上用MoKa射线收集到1714个I≥3σ(I)的独立衍射点.结构用直接法和Patte-rson法结合解出,经全矩阵最小二乘法修正,R=0.060.络合物的中心原子钒与配位体分子的比例为M:L=1:3.三个与钒配位的a-羟基乙酸中,两个是双齿螯合,并互为邻位排布,另一个则是单端络合,形成一种较为独特的配位化合物。     

Synthesis and Crystal Structure of H_2Mo_8O_(26)〔(n-Bu)_4N_2〔(CH_3)_2 COHCH_2COCH_3〕_2

1　ＩＮＴＲＯＤＵＣＴＩＯＮＰｏｌｙｍｏｌｙｂｄａｔｅａｎｉｏｎｓｈａｖｅｂｅｅｎｓｔｕｄｉｅｄｆｏｒｍａｎｙｙｅａｒｓｂｅｃａｕｓｅｏｆｔｈｅｉｒａｐｐｌｉｃａ ｔｉｏｎｉｎｃａｔａｌｙｓｉｓｃｈｅｍｉｓｔｒｙ〔1〕.Ｉｎｔｈｅｓｙｎｔｈｅｓｉｓｏｆｏｒｇａｎｉｃｐｏｌｙｍｏｌｙｂｄａｔｅｄｅｒｉｖａｔｉｖｅｓｕｓｉｎｇａｃｅｔｏｎｅａｓｓｏｌｖｅｎｔ,ｗｅｆｏｕｎｄｔｈａｔｔｈｅｃｏｎｄｅｎｓａｔｉｏｎｒｅａｃｔｉｏｎｏｆａｃｅｔｏｎｅｏｃｃｕｒｒｅｄａｎｄｔｈｅｃｏｎｄｅｎｓａｔｉｏｎｐｒｏｄ…     

CRYSTAL STRUCTURE OF Mo_3(μ_3-O) (μ-S_2)_ 3 [S_2P(OEt)_2]_3I

<正> Mr=1178.9, monoclinic, P21/n, a=16.570(2), b=12.370(1), c=20.007(2) A,β=99.97(1)°, V=4039.0A3, Z=4, Dx=1.938 Mgm-3, λ(MoKα)=0.7107A, μ(MoKα)=23.96 F(000)=2296, room temperature. Final R value=0.047 for 4387 unique observed reflections. It consists of neutral mono-oxo-capped trinuclear molybdenum cluster molecules with an average Mo-Mo bond length of 2.626(4)A and an average Mo-0 bond length of 2.036(2)8.