氮杂环卡宾-钯功能化的配位聚合物（NHC-Pd@Zn-L）：合成、表征及催化Suzuki-Miyaura交叉偶联反应

以\mathrm{1,3}-二(1-羧乙基)咪唑盐(HL)和Zn(NO₃)₂·6H₂O反应合成二维配位聚合物[Zn(L)₂] _n (Zn-L),产物再与K₂PdCl₄在四氢呋喃溶液中反应引入氮杂环卡宾-钯（NHC-Pd）催化位点,制得催化剂NHC-Pd@Zn-L,并通过PXRD、TGA、ICP、SEM、EDS和XPS进行表征。结果表明,NHC-Pd@Zn-L具有良好的热稳定性且修饰后晶体的框架结构没有发生变化,Pd以NHC-Pd的形式结合在Zn-L中,并均匀分散在配位聚合物中。将NHC-Pd@Zn-L用于催化Suzuki-Miyaura交叉偶联反应,当以苯硼酸和溴苯为底物,催化剂用量为15 mg,乙醇为溶剂,碳酸钾为碱的条件下60℃反应6 h,产率达到>99%,而且催化剂易于回收并可循环使用3次。     

成型条件对Co/ZSM-5催化剂催化分解N2O性能影响

采用挤条成型法制备Co/ZSM-5催化剂，通过X射线衍射、BET比表面积、氢气程序升温还原（H₂-TPR）、氨气程序升温脱附法（NH₃-TPD）和颗粒径向抗压碎（侧压）强度测试对催化剂进行表征，在固定床微型反应器中评价催化剂催化分解N₂O活性，对Co/ZSM-5(N-50)催化剂进行稳定性测试。结果表明，钴物种以Co₃O₄尖晶石氧化物形式存在于Co/ZSM-5催化剂中，胶溶剂种类显著影响催化剂抗压碎强度；黏合剂用量影响催化剂抗压碎强度、酸量、氧化还原性和催化剂催化分解N₂O活性；以硝酸为胶溶剂，黏合剂（SB粉）用量为30%和50%制备的催化剂，抗压碎强度大，分别为208N/cm和230N/cm，催化分解N₂O温度T ₉₅分别为485℃和500℃。在固定床微型反应器中，模拟工业尾气组成（ {\phi }_{{\mathrm{N}}_2\mathrm{O}} =11%、 {\phi }_{{\mathrm{O}}_2} =16%、N₂为平衡气），反应温度446℃、空速6000h^-1条件下，Co/ZSM-5(N-50)催化剂在1000h稳定性测试中表现出良好的催化活性和稳定性，N₂O转化率高于98%。     

La1-xLixMnO3钙钛矿催化剂同时消除NO和碳烟催化性能

采用溶剂热法制备La_1-xLi_xMnO₃ (x=0,0.05,0.15,0.25) 钙钛矿型复合金属氧化物催化剂。通过XRD、FT-IR、XPS、H₂-TPR和NO-TPD等手段对催化剂进行表征，在固定床微型反应器中评价催化剂同时消除NO和碳烟催化性能。结果表明，溶剂热法制备的La_1-xLi_xMnO₃催化剂具有单一的钙钛矿结构，催化剂中Mn物种以Mn³⁺和Mn⁴⁺的形式存在。Li⁺部分取代LaMnO₃中La³⁺后，La_1-xLi_xMnO₃催化剂上Mn⁴⁺数量和氧空位增加，促进更多活性氧物种和氮氧化物的吸附与活化，提高氧化还原性能，改善催化活性。Li⁺取代量为0.15，即La_0.85Li_0.15MnO₃催化剂催化活性较好，T_max和T_ig分别为463℃和327℃，NO最大转化率X_{\mathrm{N}\mathrm{O}}^{\mathrm{m}\mathrm{a}\mathrm{x}}为42.1%，反应温度T_{\mathrm{N}\mathrm{O}}^{\mathrm{m}\mathrm{a}\mathrm{x}}为383℃。     

碱式硫酸镁晶须的可控制备及不同离子的影响机制

以氯化镁、氢氧化钠和硫酸镁为原料,采用溶胶-凝胶-水热法制备了碱式硫酸镁（MHSH-512）晶须,研究了前驱物Mg(OH)₂、Mg²⁺和\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}的浓度和杂质离子Cl^-对MHSH-512晶须的生长机制和微观形貌的影响。研究表明,溶胶-凝胶法得到的Mg(OH)₂在水热条件下的溶解再结晶过程中易形成结构单元[Mg(OH)₆]^4-。当c(Mg²⁺)/ c(\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-})为3时,几乎全部的[Mg(OH)₆]^4-可与\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}形成晶核,并以b轴为主轴生长为MHSH-512一维晶须。大量Cl^-的存在可能阻碍OH^-与Mg²⁺相互作用,延缓[Mg(OH)₆]^4-生成,同时与\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-}在[Mg(OH)₆]^4-表面发生竞争吸附,导致晶须生长滞后,但对晶须的最终形貌和分散性没有实质影响。190℃下水热反应10 h制得的MHSH-512晶须结晶度高、长径比大（150～200）、表面光滑且分散性好,易于实现工业化生产,为青海盐湖镁资源的高值化利用提供了一条有效途径。     

湿法磷酸浸出强化及有机质去除研究

在湿法磷酸浸出过程中由于部分有机物碳化不彻底，使产品磷酸呈现黑色。本文提出了一种新型的催化氧化湿法磷酸净化技术，即在湿法磷酸浸出过程中引入氧化剂（H₂O₂）及催化剂（MnO₂），基于转化过程中形成的·\mathrm{O}\mathrm{H}和\mathrm{H}{\mathrm{O}}_{\mathrm{2}}·等过氧化物实现对有机物的去除与浸出过程的强化。重点考察不同反应条件对湿法磷酸浸出率及有机质去除的影响。结果表明，浸出时间为40 min、反应温度为80℃、H₂O₂用量为0.08 ml/g、催化剂与磷矿的质量比为0.04时，磷矿浸出率可达96.9%；同时测定得到的TOC去除率达到79%。分析机理可得，H₂O₂会与溶液中的H₃PO₄形成H₃PO₄·H₂O₂过氧化物，MnO₂与之发生类Fenton反应，产生大量·\mathrm{O}\mathrm{H}，进而将黑色有机物充分氧化为CO₂和H₂O，打破有机物对磷矿颗粒表面的“包裹”，促进磷酸的浸出和有机物的去除。     

酸性离子液体催化合成草酸二乙酯

合成了4种咪唑基酸性离子液体,用于催化草酸和乙醇酯化反应合成草酸二乙酯。考察了影响反应的主要因素,确定最佳反应工艺条件为：采用[Mim(CH₂)₃SO₃H]HSO₄离子液体为催化剂,反应温度为110 ℃,反应时间为90 min,n(乙醇)∶n(草酸)=4∶1。在此条件下离子液体循环使用4次,活性变化不明显,草酸二乙酯收率大于73%。此外,采用溶胶-凝胶法将[Mim(CH₂)₃SO₃H]HSO₄离子液体固定到SiO₂上,用于催化酯化反应。结果表明,离子液体固定化后,其酸催化性能有明显提高,草酸二乙酯收率为84.8%,且催化剂具有较好的稳定性。     

氯化氢催化氧化制氯气达到化学平衡前后的反应行为

采用氧化铝为载体的铜基复合催化剂在固定床与无梯度组合反应器上考察了氯化氢催化氧化制氯气的反应行为。在反应温度T=360~400℃、进料摩尔配比n_HCl/n_{{\mathrm{O}}_{\mathrm{2}}}=1~4、HCl空速W/F_HCl0=0.01~60h^-1以及常压条件下考察了反应温度、进料摩尔比、HCl空速等工艺条件对HCl转化率与反应速率的影响。结果表明：在到达化学平衡以前，HCl转化率和反应速率随着反应温度的升高或反应气体摩尔配比n_HCl/n_{{\mathrm{O}}_{\mathrm{2}}}的降低而升高；随着反应空速F_HCl0/W的降低，HCl转化率先逐渐升高，而HCl反应速率逐渐降低。在达到化学平衡以后，转化率随着反应温度的升高或反应气体摩尔配比n_HCl/n_{{\mathrm{O}}_{\mathrm{2}}}的升高或反应空速F_HCl0/W的降低而降低，反应速率为零。控制反应温度在390~400℃范围内，原料气摩尔比n_HCl∶n_{{\mathrm{O}}_{\mathrm{2}}}为(4∶3)~(4∶2)，HCl空速W/F_HCl0在2.5h^-1左右，此时的HCl转化率可达到60%~70%，且HCl反应速率保持在(0.2~0.25)mmol/(g·min)。本文采用的联合实验装置对于化学平衡前后的反应行为均能较好地考察，为考察与研究同类反应的反应行为开辟了新思路。     

CO耐硫甲烷化MoS2/Si-ZrO2催化剂的失活原因研究

采用等体积浸渍法制备MoS₂/Si-ZrO₂催化剂,并对其CO耐硫甲烷化的催化活性稳定性进行评估。结果表明在2H₂∶2CO∶1N₂（摩尔比）、反应压力2.5 MPa、反应温度 450℃、硫含量0.01%及质量空速 6000 ml/(g·h)的反应条件下,100 h后CO转化率下降11%。深入进行氢气程序升温还原(H₂-TPR)、X射线光电子能谱(XPS)、拉曼光谱(RS)、等离子体发射光谱(ICP-OES)、高分辨透射电子显微镜(HRTEM)、热重分析(TGA)以及元素分析等表征后,发现反应后催化剂表面无明显积炭,但出现了明显的团聚现象。而催化剂失活的根本原因是硫流失的发生,导致具有催化活性的桥键 {\mathrm{S}}_{\mathrm{2}}^{\mathrm{2}-} 物种转变为S^2-物种和H₂S。     

溶剂热浸渍法制备高稳定性Zn(OAc)2/SiO2催化剂及其催化合成苯氨基甲酸甲酯

Zn(OAc)₂对由碳酸二甲酯（DMC）和苯胺合成苯氨基甲酸甲酯（MPC）的反应具有优异的催化性能,但存在易失活、不能重复使用的缺点。为此,以DMC为溶剂,利用溶剂热浸渍法制备Zn(OAc)₂/SiO₂催化剂,并对其催化性能进行了研究。利用XRD、FTIR和TG-DTA等方法对其进行了表征,结果表明,Zn(OAc)₂/SiO₂催化剂表面存在Zn(OAc)₂和ZnO,且其在SiO₂表面分散较好;优化了Zn(OAc)₂/SiO₂催化剂的反应条件,当反应温度为190℃、反应时间为5h、苯胺与DMC的摩尔比为1∶20、催化剂与苯胺质量比为0.2时,苯胺的转化率为97.2%,MPC的选择性为89.4%。和等体积浸渍法制备的催化剂相比,溶剂热浸渍法制备的Zn(OAc)₂/SiO₂催化剂具有较好的稳定性,重复使用7次,苯胺的转化率下降至79.1%,MPC的选择性下降至79.2%。Zn(OAc)₂/SiO₂活性下降的原因是由于ZnO的生成,并对其进行了再生,再生后的催化剂活性与新鲜催化剂接近。     

含非对称Gemini离子液体二元混合体系的体积和黏度性质

在温度分别为293.15、303.15、313.15、323.15和333.15 K及大气压下,系统测定了非对称Gemini离子液体,1-(3-(三甲基铵)丙-1-基)-3-甲基咪唑双氰胺盐([N₁₁₁C₃MIM][N(CN)₂]₂),分别与乙腈(MeCN)、甲醇(MeOH)、乙醇(EtOH)所组成的二元混合物的密度和黏度。由密度和黏度值分别计算了二元混合物的超额摩尔体积(V_{\mathrm{m}}^{\mathrm{E}})和超额黏度(Δη)。V_{\mathrm{m}}^{\mathrm{E}}和Δη随组成的变化关系由Redlich-Kister方程进行了回归,得到方程参数。结果表明,V_{\mathrm{m}}^{\mathrm{E}}和Δη值与理想溶液间为负偏差,且存在最小值,说明二元体系中[N₁₁₁C₃MIM][N(CN)₂]₂和溶剂分子间相互作用力更强,同时与所研究分子的大小和形状的差异有关。同时,V_{\mathrm{m}}^{\mathrm{E}}和Δη随温度的变化关系表明,温度对研究混合物中的分子间相互作用有很大影响。     

Multi-metal cyanide catalysts for ring-opening polymerization of propylene oxide

Polymerizations of propylene oxide (PO) have been carried out by using a series of multi-metal metal cyanide (MMC) catalysts prepared by reacting ZnCl₂ and K₃[Co(CN)₆]₂, K₄Fe(CN)₆, K₃Fe(CN)₆ and/or K₂Ni(CN)₄ in the presence of tert-butyl alcohol and polytetramethylene ether glycol as complexing agents. The resulting MMC catalysts are characterized by elemental analysis, X-ray photoelectron spectroscopy, infrared spectroscopy and X-ray powder diffraction. The structure of MMC catalysts with broadened X-ray diffraction peaks is different from that of highly crystalline Prussian blue analogues of microporous crystalline materials due to the coordination of complexing agents. The PO polymerization behavior was tunable by changing with various metal cyanide salts after fixing a main catalyst component as ZnCl₂. Even if the basic structure of the MMC complexes is different each other, i.e. orthorhombic for Zn₂[Fe(CN)₆] and monoclinic for Zn₃[Fe(CN)₆]₂ and Zn₃[Co(CN)₆]₂, the chemical formulations become more complicated by forming MMC complexes through cyano bridges and complexing agents’ coordination and the structure more distorted from the defined crystal structures. All catalysts prepared by using K₃[Co(CN)₆]₂ showed very high activity once they were activated. Simply changing catalyst formulation by choosing different metal cyanide salts, catalytic activity, induction period, polymer molecular weight and its distribution and polymer viscosity could be tuned.     

Zn(OAc)2/AC催化固定床上CO2与1,2-丙二醇合成碳酸丙烯酯及其反应机理

以负载型乙酸锌为催化剂,在固定床上实现了CO₂和1,2-丙二醇(PG)合成碳酸丙烯酯(PC)反应。考察了不同载体和负载量对负载型乙酸锌催化性能的影响以及反应条件对PC合成反应的影响。结果表明:负载量为40% (质量分数)的Zn(OAc)₂/AC催化性能最好。CO₂与PG合成PC适宜的反应条件为:PG、乙腈和CO₂的摩尔比为1:1.8:11,CO₂ 压力 4.0 MPa,反应温度160 ℃和液空速0.9 h^-1。在此条件下,PC收率和选择性分别为6.3%和49.0%。采用原位红外结合设计实验研究了无水乙酸锌分别与CO₂和PG之间的相互作用,发现CO₂与乙酸锌之间的化学吸附比较弱,而PG与乙酸锌之间的化学吸附较强,能够活化PG。据此推测了乙酸锌催化CO₂与PG合成PC的反应机理。     

桥联茂金属催化1-癸烯聚合及其产物结构与性能

采用桥联茂金属催化体系rac-Et(1-Ind)₂ZrCl₂/Al(ⁱBu)₃/[Me₂NHPh]⁺[B(C₆F₅)₄]^-催化1-癸烯聚合,考察了茂金属浓度、Al/Zr摩尔比、B/Zr摩尔比、温度、反应时间对反应转化率、黏度和摩尔质量的影响.当反应条件为1-癸烯20mL、甲苯20mL、Zr/烯摩尔比8×10^-5、Al/Zr摩尔比80、B/Zr摩尔比1.5、温度80℃、反应时间1h时,转化率达到96.2%.采用¹³C NMR和¹H NMR表征了产物的结构,优化条件下所得的聚合产物具有高黏度指数(259)和低分子量分布(2.088),可作为理想的润滑油基础油的原料.     

Tuning of the activity and induction period of double metal cyanide catalyzed ring-opening polymerizations of propylene oxide by using ionic liquids

Polymerizations of propylene oxide (PO) have been carried out by using double metal cyanide (DMC) catalyst prepared by reacting ZnCl₂ and K₃[Co(CN)₆] in the presence of tert-butyl alcohol as a complexing agents. The DMC catalyst of the molecular formula, Zn_2.3Cl_1.0[Co(CN)₆]_1.0·2.0 ^tBuOH·1.0H₂O, is characterized by gas sorption measurements, infrared spectroscopy and X-ray powder diffraction. The structure of DMC catalyst with negligible surface area and broadened X-ray diffraction peaks is different from that of Prussian blue analogue, Zn₃[Co(CN)₆]₂·12H₂O of microporous crystalline materials. The PO polymerization behavior is tunable by combining it with various imidazolium based ionic liquids (ILs) as external additives. Thus, (1) they make the zinc-monomer bond faster activated during the initial stage of polymerization, (2) they make the zinc-monomer bond more active, (3) they stabilize the polymerization centers and prevent their decomposition, and (4) they improve important polymer properties such as molecular weight, viscosity and unsaturation level. The maximum rate of polymerization (R_p,max) of DMC catalyst increases from 2587 to 27,222 g-polymer/g-cat h by combining with 1-ethyl-3-methylimidazolium chloride (emimCl, [emimCl]/[Zn] = 1.25) at 115 °C. The induction period as the time to reach R_p,max becomes short from 321 min for DMC catalyst to 29 min for DMC/emimCl binary catalyst. The unsaturation value of polyol (0.017 mequiv./g) produced by DMC decreases to 0.005 mequiv./g by simply combining with IL. The molecular weight polyol produced by DMC catalyst increases from M_n = 3700 to more than 6000, and the viscosity of polyol decreases by combining with ILs.     

铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢性能研究

采用浸渍-还原法制备了铁、钴、镍、铜和锌催化剂,考察了其催化氨硼烷水解产氢性能,并优化了钴催化剂的制备条件和反应条件。结果发现,铁催化剂中铁以Fe₂B合金相存在,钴催化剂中钴以金属钴存在,镍催化剂中镍以金属镍和Ni（OH）₂·2H₂O存在,铜催化剂中铜以金属铜和氧化亚铜存在,锌催化剂中锌以Zn₄SO₄（OH）₆·4H₂O存在。铁、钴、镍、铜和锌催化剂催化氨硼烷水解产氢活性由大到小顺序为钴催化剂、镍催化剂、铜催化剂、铁催化剂、锌催化剂。显然,具有金属钴相的钴催化剂、金属镍相的镍催化剂和金属铜相的铜催化剂催化氨硼烷产氢活性高于具有Fe₂B合金相的铁催化剂。锌催化剂在制备条件下不能被还原为金属相,它几乎没有催化氨硼烷产氢活性。氯化钴与还原剂硼氢化钠的物质的量比为1∶1.3、还原温度为303 K时制备的钴催化剂催化BH₃NH₃水解产氢性能最佳。反应动力学计算表明钴催化剂催化BH₃NH₃水解产氢反应对氨硼烷浓度的反应级数为零级,对钴催化剂浓度的反应级数为一级,活化能为58 kJ/mol。     

Effects of iron precursors on the structure and catalytic performance of iron molybdate prepared by mechanochemical route for methanol to formaldehyde

Mechanochemical synthesis has been applied for many novel material preparations and gained more and more attention due to green and high-efficiency recently. In order to explore the influences of iron precursors on structure and performance of iron molybdate catalyst prepared by mechanochemical route, three typical and cheap iron precursors have been used in preparation of iron molybdate catalyst. Many characterization methods have been employed to obtain the physical and chemical properties of iron molybdate catalyst. Results indicate that iron precursors have the significant impact on the phase composition, crystal morphology and catalytic performance in the conversion of methanol to formaldehyde. It is hard to regulate the phase composition by changing Mo/Fe mole ratios for Fe_2(SO_4)_3 as iron precursor. In addition, as for Fe_2(SO_4)_3, the formaldehyde yield is lower than that from iron molybdate catalyst prepared with Fe(NO_3)_3·9H_2O due to the reduction in Fe_2(MoO_4)_3 phase as active phase. Based on mechanochemical and coprecipitation method, the solvent water could be a key factor for the formation of MoO_3 and Fe_2(MoO_4) for FeCl_3·6H_2O and Fe_2(SO_4)_3 as precursors. Iron molybdate catalyst prepared with Fe(NO_3)_3·9H_2O by mechanochemical route, shows the best methanol conversion and formaldehyde yield in this reaction.     

CO2加氢制甲醇Cu-Zn-Al水滑石催化剂的改性研究

CO₂加氢制甲醇既能有效缓解温室效应带来的全球气温升高问题,也能促进CO₂的资源化利用,成为研究热点之一。对Cu-Zn-Al水滑石(CZA-LDH)开展改性研究,以Cu(NO₃)₂·3H₂O、Zn(NO₃)₂·6H₂O和Al(NO₃)₃·9H₂O为原料,以NaOH和NaCO₃为沉淀剂,采用共沉淀法制备CZA-LDH,并在制备过程中引入聚乙二醇(PEG)、聚乙烯吡咯烷酮(PVP)和三乙醇胺(TEA),焙烧后得到4组催化剂。XRD、FT-IR、N₂吸附-脱附、SEM表征结果及催化性能测试数据表明,引入TEA的CZA-LDH焙烧后得到的复合金属氧化物催化剂(CZA-LDO-TEA)表现出最优的性能。这是因为TEA 能够破坏表面晶体结构,促进催化剂中CuO组分的还原,提高了 CO₂的化学吸附能力,从而提高了催化剂的CO₂转化率。     

CATALYTIC HYDRODECHLORINATION OF 1,2-DICHLOROETHANE AND TRICHLOROETHYLENE OVER Rh/Si0 2 CATALYSTS

Reactions of hydrogen with 1,2-dichloroethane and trichloroethylene have been investigated over Rh/Si0 ₂ catalysts at 365-553K and 0.1 MPa. The major products of the reactions are HCl and C ₂ H ₆. The selectivity for C ₂ H ₆ increases with increasing temperature. C ₂ HC ₅ Cl is a minor product for the dichloroethane reaction; partially dechlorinated products, i.e. C ₂ H ₅ Cl, C ₂ H ₄ CI ₂, C ₂ H ₃ Cl, and C ₂ H ₂ CI ₂, constitute the minor products for the trichloroethylene reaction. The selectivity for the partially dechlorinated C ₂ hydrocarbons decreases with increasing temperature. Cl dissociated from chlorinated hydrocarbons poisons the catalyst. Regeneration of catalyst by hydrogen treatment restores the catalyst to more than 70% of the initial activity for the trichloroethylene reaction. Probing the hydrogenation activity of the used Rh/Si0 ₂ and RhCl ₃ /Si0 ₂ with ethylene hydrogenation shows that the presence of CI on Rh/Si0 ₂ decreases hydrogenation but increases ethylene hydrogenolysis activities.