碳微球负载镍催化顺酐选择性加氢制备丁二酸酐

采用水热法制备了胶态碳微球(CMS),进一步制备了碳微球负载镍催化剂(Ni/CMS), 并进行了FTIR、XRD、SEM、TEM和N2吸附表征。对Ni/CMS催化顺酐(MA) 选择性加氢制备丁二酸酐(SA) 进行了考察,结果表明,以葡萄糖为碳源,经过500 ○C焙烧制备的Ni/CMS催化剂表现最佳的性能,氢气压力、反应温度和反应时间对加氢反应中顺酐转化率有很大影响。以乙酸酐作溶剂,在90 ○C、1.0 MPa H2压力、反应3小时的温和条件下,顺酐在Ni/CMS催化剂上转化率达到98.4%,丁二酸酐选择性为100%。     

镍负载型活性白土催化剂用于顺酐加氢制丁二酸酐

用5wt%镍/白土催化剂进行顺酐加氢制丁二酸酐的活性测试。并用X射线衍射（XRD）,氢气程序升温还原（TPR）和热重分析（TGA）光谱对这些催化剂进行表征。 XRD和TPR研究表明,镍是以Ni2+的形式存在于载体上,在未还原的催化剂样品上不存在单质镍和三氧化二镍。TGA研究表明,当焙烧温度达到650℃,载体的结构会被破坏。顺酐的加氢活性测试表明,550℃焙烧的催化剂加氢效果最好。在反应温度为180℃,压力为1MPa,质量空速为4h-1的条件下,顺酐的转化率达到97.14%,丁二酸酐的选择性达到99.55%。     

纳米Pd/AC催化顺酐“一锅法”水相合成丁二酸

将改性骨架镍催化剂、贵金属负载型催化剂用于"一锅法"水相顺酐催化加氢合成丁二酸,考察了催化剂种类、反应温度、反应压力、顺酐用量及催化剂用量对该反应的影响,并用XRD和TEM法对反应前后催化剂的微观结构进行了表征。结果表明,由胶体溶液法制备的负载型纳米Pd/AC(AC为活性炭)催化剂的性能最好。在353 K、1.0 MPa、顺酐1.96 g、水20mL、2%(w)Pd/AC催化剂0.020 g的优化条件下反应177 min时,顺酐转化率达100.0%,丁二酸选择性达99.8%。Pd/AC催化剂的稳定性实验结果显示,该催化剂连续使用10次后仍能维持较高的活性和选择性。新鲜Pd/AC催化剂中Pd颗粒分散均匀,粒径为1～4 nm;连续使用10次后Pd/AC催化剂部分发生团聚,但仍存在大量的纳米级Pd晶粒,使反应稳定进行。     

Mechanochemical-treated Cr-promoted Vanadyl Pyrophosphate Catalyst for n-Butane Oxidation to Maleic Anhydride

Abstract

Cr-promoted vanadium phosphate (VPO) catalyst was synthesized by mechanotreating VOHPO₄·0.5H₂O in cyclohexane for 2 hr using a high energy planetary ball miller followed by calcination in a flow of n-butane/air mixture at 673 K. The physico-chemical properties of the sample were investigated by several characterization techniques such as BET, XRD, redox titration, SEM, and TPR. The data were compared to the unmilled material. BET surface area measurement of the milled catalyst showed that it possesses higher surface area (13.2 m² g^?1) compared to the unmilled catalyst (6.4 m² g^?1). Milling also caused a slight increment in the average oxidation state of vanadium as well as the percentage of V⁵⁺ oxidation state. XRD pattern of the milled material revealed that the major diffraction peaks were broadened thus indicating a reduction of particle size. SEM micrographs showed the lost in the blossom morphology and the formation of layer packages, with more circular particles in the milled catalyst. The amount of active lattice oxygen species being removed from V⁴⁺-O^? pairs increased significantly for mechanochemical treated Cr-doped VPO catalyst leads to the enhancement of the catalytic activity for n-butane oxidation to maleic anhydride.     

顺酐气相加氢Cu-Zn-Ti催化剂的研究

以共沉淀法制备了Cu-Zn-Ti系列催化剂,采用XRD、XPS、TPR等分析手段,表征了催化剂结构,进行了顺酐气相加氢的活性评价。结果表明,用TiO2作载体材料可以取得较大的比表面积。Cu-Zn-Ti是优良的顺酐气相加氢催化剂,且γ-丁内酯收率最高可达到98％。同时对Cu-Zn-Ti催化剂催化顺酐加氢反应机理进行了探讨。     

W 对 W-Ni2P/SBA-15催化剂结构及二苯并噻吩氢脱硫性能的影响

 以硝酸镍为镍源,磷酸氢二铵为磷源,介孔分子筛 SBA-15为载体,采用共浸渍法制备Ni₂P/SBA-15前驱体,再将一定量的偏钨酸铵水溶液引入,采用程序升温还原制备了一系列 W-Ni₂P/SBA-15催化剂。采用 XRD、N₂吸附-脱附、NH₃-TPD 和 XPS 表征了催化剂的结构,并评价了催化剂的二苯并噻吩加氢脱硫活性。结果表明,W-Ni₂P/SBA-15催化剂中均只存在Ni₂P物相;催化剂的比表面积和孔体积随着W含量的增加先增大后减小;强酸量和总酸量都随W含量的增加有明显增加;W的加入使得催化剂表面的 Ni^δ+含量有所降低,而 P^δ-含量有所增加;在大于360℃时,催化剂对二苯并噻吩具有很好的深度加氢脱硫活性,并且以直接脱硫生成联苯的脱硫机理为主。     

The Effect of Cr,Ni, Fe,and Mn Dopants on the Performance of Hydrothermal Synthesized Vanadium Phosphate Catalysts for n-Butane Oxidation

Abstract

Vanadium phosphorus oxide (VPO) catalysts synthesized via hydrothermal method were introduced with some different dopants, Cr, Ni, Fe, and Mn during the preparation of the precursors, VOHPO₄ · 0.5H₂O. All modified precursors were subsequently transformed under reaction conditions to give the active phase, (VO)₂P₂O₇. Several techniques were used to characterize the physicochemical properties of the catalysts, such as X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), H₂-temperature programmed reduction (TPR), laser Raman spectroscopy (LRS), and chemical analysis. The catalytic performance of the catalysts for selective oxidation of n-butane to maleic anhydride has been carried out by using a fixed bed microreactor (673 K, gas hourly space velocity [GHSV] = 2,400 hr^?1). The results show that the addition of dopants into the VPO catalysts increased the surface area of the catalysts and induced the formation of V⁵⁺ phases as shown in XRD and LRS spectra that promoted the catalytic performance. A further water reflux treatment to all the precursors gave catalysts with only (VO)₂P₂O₇ phase. However, the activity and selectivity of these catalysts were reduced markedly.     

微量TiO2对Ni/SiO2催化剂催化顺酐加氢制γ-丁内酯的促进作用

 采用等体积浸渍法分别制备了Ni/SiO₂和含TiO₂的Ni/SiO₂催化剂,采用XRD、TPR、XPS、N₂吸附-脱附技术对催化剂进行了表征,并将催化剂应用于顺酐液相加氢制γ-丁内酯反应中,考察了Ni含量、TiO₂添加量、催化剂还原温度对催化剂活性的影响。结果表明,Ni/SiO₂催化剂对顺酐液相加氢制γ-丁内酯反应具有很高的催化活性, γ-丁内酯选择性很高;Ni/SiO₂添加微量助剂TiO₂,可以提高该反应的γ-丁内酯选择性。推测可能是由于TiO₂促进了催化剂的还原,产生更多的活性中心,并且在400℃还原时,Ni和TiO₂之间产生了强金属-载体相互作用（SMSI效应）,TiO₂富集到Ni的表面,将电子转移到Ni上,产生了更多有利于吸附羰基的活性中心,从而提高了γ-丁内酯选择性。     

The Effect of Pd Precursors on the Catalytic Activity of a Pd/Al2O3 Catalyst for Cumene Hydroperoxide Hydrogenation

Abstract

Abstract Pd/Al₂O₃ catalysts were prepared by wet impregnation using K₂PdCl₄, (NH₄)₂PdCl₄, and Pd(NO₃)₂ as precursors. All catalysts were characterized by means of inductively coupled plasma-atomic emission spectroscopy (ICP-AES), temperature-programmed reduction (TPR), X-ray diffraction (XRD), and CO chemisorption. The results obtained in the hydrogenation of cumene hydroperoxide (CHP) to α-cumyl alcohol (CA) showed that Pd/Al₂O₃ catalyst prepared from Pd(NO₃)₂ exhibited the highest turnover frequency (TOF) value and the greatest deactivation extent, whereas Pd/Al₂O₃ catalyst prepared from (NH₄)₂PdCl₄ displayed the lowest TOF value but the best stability.     

Cu-Zn-Ce催化顺丁烯二酸酐气相加氢

采用共沉淀法制备了一系列Cu-Zn-Ce催化剂,在反应压力1MPa,反应温度220～280℃的条件下,进行顺丁烯二酸酐(MA)气相加氢活性测试,MA转化率接近100%,γ-丁内酯选择性达91.93%。同时正丁醇发生脱氢-歧化-酯化反应,可提供MA加氢耗氢量4.14%～59.67%的氢气。用XRD、TPR、N_2吸附等手段对催化剂进行了表征,结果表明:采用超声共沉淀法可以制得粒径小、比表面积大的催化剂;加入ZnO可以促进Cu~(2+)还原,提高活性Cu~0组分的分散程度;CeO_2与ZnO的协同作用可以提高催化剂的活性。     

后处理温度对NiO/SiO_2气凝胶催化剂顺酐选择加氢性能的影响

采用TEM、XRD、TPR等物理表征技术和液相选择加氢活性评价 ,研究了焙烧和还原温度对以正硅酸乙酯和硝酸镍为原料用溶胶凝胶超临界流体干燥法制备的NiO/SiO2 气凝胶催化剂性能的影响。结果表明 ,在研究的温度范围内催化剂的织构和结构具有良好的热稳定性 ;焙烧温度高于 6 73K导致γ 丁内酯选择性下降 ;H2 还原温度对加氢性能的影响随镍含量不同而异 ,当镍含量≤ 1 3%时 ,还原温度升高加氢活性升高 ,镍含量≥ 1 3%时 ,还原温度升高不利于加氢反应的进行。     

铋掺杂钒磷氧催化剂选择性氧化碳四烃制顺酐

制备了Bi掺杂的钒磷氧(VPO)催化剂(VPOBi);分别以正丁烷和混合碳四为原料,考察了Bi掺杂量对VPOBi催化剂选择性氧化碳四烃性能的影响。在653K、气态空速2000h~(-1)条件下,正丁烷在Bi掺杂量(摩尔分数)为0.3%的VPOBi催化剂上所得顺酐收率最大(40.4%),混合碳四在Bi掺杂量为0.2%的VPOBi催化剂上所得顺酐收率最大(49.2%)。采用XRD,BET,SEM,H_2-TPR等方法对催化剂进行表征。表征结果表明,Bi的掺杂使VPO催化剂中暴露的(020)晶面显著增多,改变了催化剂的形貌,增大了催化剂的比表面积,提高了催化剂晶格氧的反应性能,使晶格氧能在相对较低的温度下被H_2还原,从而显著改善了VPO催化剂选择性氧化碳四烃制顺酐的性能。     

金属助剂对Ni2P/SBA-15催化剂结构及二苯并噻吩加氢脱硫性能的影响

 以介孔分子筛SBA-15为载体,硝酸镍为镍源,磷酸氢二铵为磷源,采用共浸渍法制备了 P/Ni 摩尔比为0.8的 Ni₂P/SBA-15催化剂,然后添加 Li、Na、K、Mg、Ca、Sr 和 Ba 等金属助剂,制备了一系列不同金属助剂的M-Ni₂P/SBA-15(其中M为 Li、Na、K、Mg、Ca、Sr 和 Ba)催化剂。采用 XRD 对该系列催化剂的结构进行了表征,并以二苯并噻吩质量分数为1%的二苯并噻吩/十氢萘溶液为模型化合物,在微型固定床反应器上评价它们的加氢脱硫(HDS)性能。结果表明,M-Ni₂P/SBA-15催化剂的活性相为 Ni₂P。不同的金属助剂对催化剂性能的促进作用不同,其中碱土金属Ca能够明显地提高 Ni₂P/SBA-15催化剂的 HDS 活性,Ca 质量分数为3.5%的Ca-Ni₂P/SBA-15催化剂的 HDS 活性最好。在反应压力3.0 MPa、反应温度360℃的条件下,3.5%Ca-Ni₂P/SBA-15催化剂催化的二苯并噻吩 HDS 的转化率达到98.6%。不同金属助剂以不同方式影响加氢脱硫反应的机理。       

Fischer-Tropsch synthesis in a slurry reactor in the presence of nanosized cobalt catalysts synthesized in situ in a hydrocarbon medium

Fischer-Tropsch synthesis in a slurry reactor at a pressure of 20 atm and a temperature of 220–300°C in the presence of 100Co : 2Pd : (5–50)Al₂O₃ and 100Co : 2Pd : (20–50)ZrO₂ (parts by weight) catalysts in situ synthesized in a hydrocarbon medium has been studied. The catalysts were prepared by the decomposition of cobalt salts and promoters in melted petroleum paraffin P-2 at 300°C and in situ reduced with hydrogen. It has been found that the nanocatalyst containing 20 parts by weight of ZrO₂ exhibits the highest activity in the Fischer-Tropsch synthesis and provides the yield of liquid products of 70 g/m³ at a CO conversion of 80%.     

Mechanochemical-treated Cr-promoted Vanadyl Pyrophosphate Catalyst for n-Butane Oxidation to Maleic Anhydride

Cr-promoted vanadium phosphate (VPO) catalyst was synthesized by mechanotreating VOHPO₄·0.5H₂O in cyclohexane for 2 hr using a high energy planetary ball miller followed by calcination in a flow of n-butane/air mixture at 673 K. The physico-chemical properties of the sample were investigated by several characterization techniques such as BET, XRD, redox titration, SEM, and TPR. The data were compared to the unmilled material. BET surface area measurement of the milled catalyst showed that it possesses higher surface area (13.2 m² g^-1) compared to the unmilled catalyst (6.4 m² g^-1). Milling also caused a slight increment in the average oxidation state of vanadium as well as the percentage of V⁵⁺ oxidation state. XRD pattern of the milled material revealed that the major diffraction peaks were broadened thus indicating a reduction of particle size. SEM micrographs showed the lost in the blossom morphology and the formation of layer packages, with more circular particles in the milled catalyst. The amount of active lattice oxygen species being removed from V⁴⁺-O^- pairs increased significantly for mechanochemical treated Cr-doped VPO catalyst leads to the enhancement of the catalytic activity for n-butane oxidation to maleic anhydride.     

Change of asphaltene and resin properties after catalytic aquathermolysis

Resin and asphaltene were separated from Liaohe heavy oil. Catalytic aquathermolysis of asphaltene and resin was investigated by using water soluble catalysts （NiSO4 and FeSO4） and oil soluble catalysts （nickel naphthenate and iron naphthenate）. Before and after aquathermolysis, the properties of the resin and asphaltene was compared by means of ultimate analysis, vapor pressure osmometer （VPO） average molecular weight, X-ray diffraction （XRD）,^13C and ^1H nuclear magnetic resonance （NMR）. The conversion sequence was as follows： No-catalyst〈NiSO4〈FeSO4〈nickel naphthenate〈iron naphthenate. In the presence of catalysts, the amount of H2 and CO increased significantly, while H2S in the gas product decreased. The molecular weight of asphaltene and resin increased after reaction without catalyst. But the catalysts restrained this trend. The H/C ratio of asphaltene and resin decreased after reaction. From the results of average structural parameters and molecular weight, it was found that asphaltene and resin were partly aggregated after aquathermolysis.     

焙烧条件对Ni-Sn-Cr/AC催化乙酸甲酯气相羰基化合成醋酐反应性能的影响

以活性炭(AC)为载体,采用等体积浸渍法制备了Ni-Sn-Cr/AC催化剂,在连续流动固定床反应器上考察了焙烧温度、焙烧时间和焙烧气氛等热处理条件对该催化剂催化乙酸甲酯气相羰基化合成醋酐反应性能的影响;同时用扫描电子显微镜、X射线衍射和N_2物理吸附等方法表征了该催化剂的结构。实验结果表明,焙烧温度和焙烧时间对催化剂活性的影响较为显著,而焙烧气氛对催化剂活性的影响不大。在N_2气氛中于600℃下焙烧4 h后的Ni-Sn-Cr/AC催化剂具有较高的羰基化活性;在n(CO):n(H_2)=8、n(CH3COOCH3):n(CH_3I)=7、n(CO):n(CH_3COOCH_3)=4、反应温度205℃、反应压力5.5 MPa、气态空速1 200 h~(-1)的条件下,乙酸甲酯的转化率、醋酐的选择性和收率分别达到38.8%,81.1%,31.5%。     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

Cu-Ni/ZnO双金属催化剂上顺酐加氢反应的研究

用共沉淀法制备了 Ｃｕ Ｎｉ／ Ｚｎ Ｏ 双金属催化剂, 用 Ｔ Ｐ Ｒ 和 Ｘ Ｒ Ｄ 等方法并结 合顺酐加氢反应对催化剂中组分间的相互作用进行了研究。结果表明, Ｚｎ Ｏ 对 Ｃｕ Ｏ 具有分散作用, 能促进 Ｃｕ Ｏ 的还原; 而与 Ｎｉ Ｏ 有强相互作用, 使后者较难还原, Ｃｕ 与 Ｎｉ 也存在相互作用。催化剂在还原过程中存在诱导期和还原期, 首先 Ｈ２ 缓慢还原出少量 Ｃｕ , Ｃｕ 又解离吸附 Ｈ２ 为活泼 ［ Ｈ］ , ［ Ｈ］ 能较快地还原 Ｎｉ Ｏ 和 Ｃｕ Ｏ, 并形成 Ｃｕ３８ Ｎｉ 合金。     

邻二甲苯氧化制苯酐“80克工艺”催化剂的研究

研究了载于环状载体上的Ｖ－Ｔｉ系二段床催化剂中的活性组份二氧化钛和有关助剂银、锌、磷、锑、铷等金属氧化物对催化剂性能的影响。放大制备的高负荷上、下两段床催化剂,经单管评价表现出较好的活性和选择性。在空速３０００ｈ－１、邻二甲苯的投料质量浓度＞８０ｇ／ｍ３条件下,邻二甲苯转化率为～１００％,粗苯酐质量收率＞１０８％,苯酞质量分数＜００４％。长时间运转试验表明,该催化剂具有良好的稳定性,重复性试验也取得了满意的结果。