用于脂肪醇胺化的三元催化剂Cu-Ni-La的研究

脂肪醇胺化制备单长链叔胺工艺的技术关键之一在于催化剂的选择性。以月桂醇与二甲胺反应评价了以Cu和Ni为活性组分,碳酸钙为载体的负载型三元催化剂Cu-Ni-La的选择性,并对该催化剂进行了XPS研究。结果发现,在相同的铜镍比条件下,稀土元素La的加入降低了产物中高沸物双长链叔胺的生成量,La的加入对氧化态Cu的还原无明显影响,但抑制了氧化态Ni的还原,而催化剂的选择性与催化剂中的Ni的还原程度密切相关。     

镍与铜的相互作用对于苯甲醇催化氧化性能的影响

通过共沉淀法制备了不同配比的Ni-Cu催化剂,并采用XRD、TPR和XPS表征方法研究了镍铜相互作用对苯甲醇的催化氧化性能的影响。结果显示,当催化剂体系中只有Ni时,催化剂组分为Ni(OH)₂;当催化剂体系含有Ni和Cu时,催化剂组分为Ni(OH)₂和Cu(OH)₂混合晶相;当催化剂体系中仅含Cu时,催化剂组分为CuO;并且由于镍、铜的相互作用,催化剂的还原温度降低,Ni的存在阻止了Cu(OH)₂晶相转变为CuO。此外,催化剂体系中Ni含量越高,其催化活性也越高,Ni的存在提高了Cu的催化性能。     

助剂对Ni/SiO2催化剂1,4-丁炔二醇加氢性能的影响

通过分步浸渍法在Ni/SiO 2催化剂中分别引入Zn、Cu、La、Mo、Co金属助剂,结合N 2物理吸附-脱附、XRD、H 2-TPR和NH 3-TPD等表征手段研究金属助剂对1,4-丁炔二醇加氢性能的影响。结果发现,Mo的引入使Ni/SiO 2催化剂的初始活性大幅增加,但反应2 h后活性下降,归因于催化剂表面酸中心使催化剂积炭失活;引入Cu、La及Co后的催化剂活性较低,推测是由于催化剂表面产生强吸附氢物种,不利于1,4-丁炔二醇加氢反应进行;与其他样品相比,Zn的引入使催化剂保持了Ni/SiO 2催化剂高的1,4-丁炔二醇加氢活性,同时可有效降低产物中2-羟基四氢呋喃副产物含量,提高目标产物1,4-丁二醇收率。     

醇法制叔胺胺化催化剂的研究

脂肪醇在催化剂作用下直接胺化催化反应是目前生产长链烷基二甲基叔胺的主要工艺。该工艺的技术关键之一在于其催化剂。研究了在以Cu和Ni为活性组分、以碳酸钙为载体的催化剂体系中加入其他金属元素作为助催化剂对催化剂选择性和活性的影响，并考察了助催化剂的加入对催化剂结构的影响，测定了各催化剂的吸附等温线、比表面积和孔径及其与催化剂活性的关系。研究结果发现：助催化剂La、Ba和Zn的加入均能提高Cu—Ni催化剂的选择性，Ba的效果尤其明显，可以将产物中双长链烷基二甲基叔胺的质量分数降低至2％以下。助催化剂的加入没有改变催化剂的孔结构，但使催化剂的比表面积和孔径均减小，降低了催化剂的活性。     

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。     

第三组分对Cu-Ni脂肪醇胺化催化剂的影响

目前制备单长链烷基二甲基叔胺的主要工艺是由脂肪醇和二甲胺在脱氢 加氢类催化剂的作用下进行胺化反应。研究了加入第三金属元素组分对以Cu和Ni为活性组分、以碳酸钙为载体的催化剂选择性的影响。发现金属元素La和Ba的加入,提高了催化剂的选择性,降低了反应产物中高沸物双十二烷基甲基叔胺的含量。Al的加入却大大降低了催化剂的选择性。     

金属／MgO上的乙醇水蒸气重整制氢

研究了氧化镁负载镍、铁、钴、锰、钼、铜和锡等金属催化剂在乙醇水蒸气重整反应的性能,结果表明在650℃,101．3kpa条件下,所有催化剂的活性都较高,乙醇接近完全转化,而对氢的选择性顺序为：Ni〉Co〉Sn〉Cu〉Fe〉Mo〉Mn。除镍的选择性是随温度上升之外,其他催化剂的选择性都随温度变化有个最佳值。镍催化剂的TPR和XRD表征表明,催化剂中存在3种形态的镍。     

关于制取长链烷基N,N—二甲基叔胺的催化剂的研究

N,N-二甲基长链烷基胺类系重要的脂肪族化合物。例如,可作为工业中间体生产出如季铵盐、氧化胺等多种产品。这类N,N-二甲基长链烷基胺已经能经济地由相应的醇在多种非均相催化剂作用下合成。但是,这些催化剂在活性和选择性方面不够令人满意。通过对醇类胺化反应机理作过长期考查,要求此反应用催化剂具备脱氢和氢解能力。作者在此项研究中,采用铜作为脱氢催化剂、镍为氢解催化剂,发现载于SiO_2/Al_2O_3上的Cu、Ni催化剂在十二烷基醇的胺化反应中显示出高活性和选择性。Cu/Ni重量比是1/1时,活性和选择性最高。用ESCA分析催化剂表面金属的价态,在200℃氢气中将铜还原成Cu~0或Cu~ 。但在同样气流下不能还原镍。当催化剂表面有大量Ni~(2 )时胺化反应的选择性低,Ni~(2 )似乎促进了二甲基胺(DMA)的歧化反应。     

QHS-3型钠钙浮选剂用催化剂生产过程中含铜、镍离子废水的处理

对QHS-3型钠钙浮选剂用催化剂生产过程中产生的含铜、镍离子废水采用常规中和沉淀法与加入金属螯合剂M相结合的方法进行了去除铜、镍离子的研究,结果表明:在最佳工艺条件下,即在溶液的pH值为9.2,聚丙烯酰胺(PAM)加入量为6 mg/L,金属螯合剂M投加量为80～90 mg/L时,处理后的废水中的铜、镍离子的质量浓度达到了国家排放标准.     

不饱和脂肪酸甲酯加氢Cu-Ni/SiO_2催化剂的研究

针对铜镍二元催化剂活性低、难过滤及容易造成金属在加氢产物中残存等问题,开展了用于不饱和脂肪酸甲酯加氢的高活性、易过滤、低金属残存Cu Ni/SiO2催化剂的研究。以特制的、具有固定物性参数的SiO2做载体,是本催化剂的特点。通过控制铜镍比和不陈化解决了金属残存问题,且红外光谱表明,产物不发生异构。催化剂制备方法和条件为:并流沉淀,趁热过滤;铜镍总量与SiO2质量比为4∶1;铜镍质量比为1∶2 5;焙烧温度350℃左右,焙烧时间3h。该催化剂优点为:不需单独还原易于保存,反应速率快,加氢活性高,催化剂用量为甲酯质量的0 5%,1MPa氢压,反应30min条件下,产物碘值可由110降到5以下。     

Amination of alcohols, using Cu/Ni-based colloidal catalyst, for consecutive reaction system

Animation of dodecyl alcohol and monomethylamine (MMA, di-functional) using Cu/Ni-based colloidal catalyst stabilized by barium stearate, and its kinetic study were performed to effectively synthesize didodecylmethylamine (DDMA). For the initial 3–4 h when MMA/dodecyl alcohol mole ratio was less than 1, the amination reaction proceeded very fast (72 mole-alcohol h^-1 mole-Cu at 200 °) by zero-order kinetics to directly produce DDMA (85%), with complete consumption of MMA, without liberation of the intermediate, momomethyldodecylamine (MMDA) at all. Then, immediately after the mole ratio exceeded 1, the amination proceeded very slowly (3.4 mole-alcohol h^-1 mole-Cu) by consecutive mechanism (second order) with liberation of MMDA. Aldolization of dodecyl aldehyde, formed by dehydrogenation of dodecyl alcohol, was found to be catalyzed by methylamines. Maintaining the zero-order kinetics by continuous control of MMA/alcohol mole ratio at less than 1 through out the amination is essential to obtain a highest DDMA yield by preventing the unwanted aldolization and transalkylation of MMA leading to various byproducts. Catalytic activity of the colloidal catalyst was sevenfold active than that of corresponding solid ones. Amination of 1,6-hexanediol and dimethylamine, using the colloidal catalyst and liquid paraffin as a solvent, was proceeded by consecutive mechanism to form N,N,N,N-tetramethyl-l,6-hexamethylenediamine with an yield of 80%.     

Cu/Ni colloidal dispersions stabilised by calcium and barium stearates for the amination of oxo-alcohols

Bimetallic Cu/Ni colloidal dispersions (the core catalyst) stabilised by a combination of calcium and barium stearates as protective colloids (catalyst C) showed a remarkable catalytic activity-several times higher than that of the core catalyst stabilised by barium stearate only (catalyst A) for the amination reaction of low reactive oxo-alcohols, having steric hindrance by branched alkyls, with dimethylamine to prepare N,N-dimethyl tertiary amines. Application of the catalyst C for the same amination reaction of dodecyl alcohol could be performed at a lower catalyst concentration of even 100 ppm based on copper at 220° C with a tertiary amine yield of 92% in a three hours' reaction. The reaction mixture containing catalyst C formed a gel at room temperature and formed a stable homogeneous solution with acetone as a polar solvent. It is postulated that water-repellency of calcium stearate and further incorporation of barium stearate as a second promoter yields a doubly stabilised structure for the core catalyst resulting in a remarkable increase in catalytic activity.     

La2O3助剂对Ni/γ-Al2O3/堇青石结构化催化剂催化加氢合成间苯二胺性能的影响

研究助剂La2O3对Ni/γ-Al2O3/堇青石结构化催化剂结构与性能的影响。采用悬浮液涂层法、活性组分浸渍法制备不同La2O3助剂含量的Ni/γ-Al2O3/堇青石结构化催化剂。通过BET、XRD、TPR、XPS对催化剂进行表征,发现不添加La2O3助剂时活性组分以NiAl2O4形式存在,添加La2O3助剂后则以NiAl2O4和NiO两种形式存在,易还原NiO的生成提高了催化剂的活性。添加La2O3助剂还能使催化剂的比表面积降低和孔尺寸增大,活性评价表明助剂La2O3存在适宜添加量,即La含量为3%。同时发现助剂La2O3对选择性的影响大于活性,La2O3具有结构助剂的特点。     

Memory effect-enhanced catalytic ozonation of aqueous phenol and oxalic acid over supported Cu catalysts derived from hydrotalcite

Mg/Al supported metal (Fe, Co, Ni and Cu) oxide catalysts were prepared by co-precipitation of hydrotalcite-like clay materials as precursors, calcined, and used for the ozonation reaction of phenol and oxalic acid. The reaction was carried out using the catalyst and aqueous solution of phenol or oxalic acid in an O₃/O₂ mixed gas-flow at 20 °C. In the ozonation of phenol, the combination of ozone and supported metal oxide catalysts was effective for the removal of total organic carbon (TOC). Also in the ozonation of oxalic acid as the main TOC component, Cu/Mg/Al catalysts showed the highest activity, followed by Ni/Mg/Al catalyst, while both Fe/Mg/Al and Co/Mg/Al catalysts were not active. Leaching of Cu and Ni, probably due to the chelation of metals by oxalic acid, was significantly observed at the beginning of the reaction. However the metal leaching disappeared at the end of the reaction possibly due to the entire consumption of oxalic acid during the reaction. The best result of oxalic acid mineralization was observed over Cu/Mg/Al catalyst calcined at 600 °C, on which least leaching of the metal was detected. Moreover, a “memory effect” of hydrotalcite accelerated the mineralization of oxalic acid over the Cu/Mg/Al catalyst; oxalate anions were captured and decomposed in the reconstituted hydrotalcite interlayer space on the surface of the Cu/Mg/Al catalyst, resulting in a remarkable enhancement in the catalytic activity of the ozonation.     

助剂改性FeOOH及其煤直接液化催化活性

采用共沉淀法分别引入Si、Al、La、Ca、Mg、Zr、Cu、Ni和Co 9种助剂元素对FeOOH催化剂改性,借助BET、XRD、SEM手段表征各助剂对催化剂微观结构、晶相和形貌的影响,在0.5 L高压釜内测试各催化剂对神东煤的直接液化催化活性。结果表明,引入Si、Al、Ca、Zr、Ni、Co能改善催化剂比表面积和分散度,分别提高煤液化油收率0.7～2.7个百分点;Ni和Co为最优助剂,Mg没有促进作用,Cu、La降低了油收率。研究表明,Al、Ca、Zr是通过结构支撑改善催化剂的织构性质,促进生成易于转化为活性相的小晶粒g-FeOOH,Ni、Co主要起到电子型助剂作用,通过强化对氢气的活化,促进煤的转化,提高油收率。     

硫化型NiMo加氢催化剂制备与表征

以四硫代钼酸铵溶液和硝酸镍溶液为浸渍液,根据活性组分Ni和Mo浸渍顺序的不同,采用真空饱和浸渍法制备了MN系列和NM系列 NiMoS/γ-Al₂O₃催化剂。在固定床加氢中试反应装置上研究了NiMoS/γ-Al₂O₃催化剂对二苯并噻吩加氢反应的催化性能,结果表明,NiMoS/γ-Al₂O₃催化剂对二苯并噻吩加氢反应具有良好的活性和选择性。Ni助剂的加入,有利于二苯并噻吩加氢反应的活性和选择性。MN-0.3为最优NiMoS/γ-Al₂O₃催化剂。在空速10 h^-1、反应压力2.0 MPa、氢油体积比300∶1、氢气预处理温度320 ℃和反应温度300 ℃条件下,催化剂对二苯并噻吩加氢反应转化率达83.9%,加氢反应活性较高。     

Promotion effect of cerium and lanthanum oxides on Ni/SBA-15 catalyst for ammonia decomposition

CeNi/SBA-15 and LaNi/SBA-15 catalysts were prepared by deposition–precipitation (DP) method and characterized by N₂ physical adsorption, XRD, H₂-TPR, H₂-chemisorption and TEM. Their catalytic performances in the ammonia decomposition reaction were tested and compared with Ni/SBA-15 catalyst. Addition of cerium and lanthanum oxides to the Ni/SBA-15 catalyst caused some decrease of BET surface area and pore volume of the catalysts, but led to a promotion effect to their catalytic activity which was closely related to the ratio of Ce (La)/Ni. The highest conversion of ammonia could be obtained when the Ce (La)/Ni ratio was around 0.3. The promotion effect is more evident on CeNi/SBA-15(0.3) than on LaNi/SBA-15(0.3) catalyst under identical reaction conditions. The CeNi/SBA-15 and LaNi/SBA-15 catalysts show smaller nickel particle size and easier reducibility in comparison with the Ni/SBA-15 catalysts.