CuZnAl/碳纤维复合材料催化合成气制备低碳醇

采用共沉淀法制备CuZnAl类水滑石,将其担载于活化碳纤维（ACFs）表面,通过焙烧还原合成功能化复合催化剂（CuZnAl/ACFs）。借助XRD、FT-IR及N₂吸附-脱附等方法对该复合物进行表征,并将其应用于合成气制备低碳醇的反应中,进行活性评价。结果表明,复合催化剂中活性组分在碳纤维表面均匀分散,碳纤维表面催化剂的颗粒尺寸减小,比表面积增大。ACFs的导电性加速醇合成过程中的电子传递,促进反应进行,因而CO转化率的提高（最高可达47%）。同时,ACFs提高催化剂表面ZnO的分散度,从而促进Cu与ZnO形成金属氧化物界面。这有利于低碳醇的生成,因而使C2以上醇的选择性高达39%。     

La促进CuCo催化剂上合成气转化制低碳醇的研究

利用超声辅助的反相共沉淀法制备了合成气选择转化制低碳醇用CuCo基催化剂。研究稀土La助剂对CuCo基复合氧化物催化剂结构的影响和催化性能的促进作用,借助X射线衍射(XRD)、N₂吸附等温线(BET)和程序升温脱附(CO-TPD)等测试技术对催化剂进行表征,并以CO加氢合成低碳醇为模型反应对其催化性能进行评价。结果表明,La助剂的添加使催化剂晶粒细化,显著加大了比表面积,促进了合成醇活性位的形成,提高了催化剂表面较强吸附CO物种的浓度,从而明显提高催化剂的活性与C_2＋醇选择性,有效调节了低碳混合醇中甲醇的含量。     

沉淀方法对FeMnCu/ZnO合成低碳醇催化剂性能的影响

以分步连续沉淀法和共沉淀法制备了一系列FeMnCu/ZnO复合氧化物合成低碳醇催化剂，对其CO加氢合成低碳混合醇的反应性能进行了考察，并用ICP、XRD、BET、H2-TPR对其结构进行了表征。结果表明，沉淀方法不同对催化剂的催化性能有较大的影响。在T503K、P=8.0MPa，GHSV=8000h－1，H2/CO＝2(体积比)的条件下, 分步沉淀法制备的FeMnCu/ZnO催化剂醇的收率和C2+OH的质量分数均高于共沉淀法制备的催化剂。其中“Fe atop Cu”催化剂醇的收率最高，达到0.26g/mLcat·h，同时“Fe atop Cu”催化剂C2+OH的质量分数也最高，可达31.72%。XRD研究表明，分步沉淀法制备的催化剂促进了CuO和ZnO的分散，提高了催化剂的催化性能。BET测试结果表明，分步沉淀法有扩孔的作用，有利于长链醇的生成。TPR研究发现，共沉淀法制备的催化剂Cu物种较难还原，这是共沉淀催化剂合成醇性能较低的原因之一。     

凹凸棒石负载Cu-Fe-Co基催化剂组合体系用于CO加氢制备低碳醇

采用浸渍法(IM)和浸渍燃烧法(IMSC)制备了凹凸棒石(ATP)及凹凸棒石-多孔硅胶微球混合物(ATPS)负载CuFe-Co基改性费托催化剂,通过N_2吸附-脱附、X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)、H_2-程序升温还原(H_2-TPR)和CO_2-程序升温脱附(CO_2-TPD)等手段对催化剂进行了表征,并将它们应用于CO加氢制备低碳醇反应。结果表明,IMSC较IM制备催化剂更有利于CuO的负载、分散和还原,促进H_2和CO与Cu活性位的接触,但两者的最佳低碳醇合成温度均为280℃。通过对ATP和ATPS负载Cu-Fe-Co基催化剂(CFCK/ATP、CFCK/ATPS)与Cu/ZnO/Al_2O_3(CZA)甲醇催化剂的组合体系的优化,获得较理想的低碳醇合成催化剂组合体系CZA║CFCK/ATPS-IMSC。利用它们之间的"产物转化耦合效应",实现CO转化率为46.3%,低碳醇选择性为39.6%,C_(2+)醇含量为22.7%。     

射频等离子体技术制备合成低碳醇用新型Cu-Co/SiO_2催化剂(英文)

采用射频等离子体技术制备新型Cu-Co/SiO2催化剂.与直接焙烧制备的样品相比,射频等离子体处理提高了催化剂的比表面积,显著增大了活性物种Co的表面含量,有效改进了催化剂的还原性能.以CO加氢合成低碳混合醇为模型反应,在563K,5.0MPa,6000h-1,V(H2)∶V(CO)=1.6的条件下,等离子体处理和等离子体处理后再焙烧样品比673K焙烧样品的催化活性提高30.46%和65.30%,低碳醇的时空收率分别提高58.22%和76.11%.     

Co在超细Mo-Co-K催化剂合成低碳醇中的作用

采用BET、XPS和TPD表征手段对超细Mo-Co-K催化剂的织构、表面结构和吸附行为进行了研究，结合催化剂的合成低碳醇性能，论证了Co在超细Mo-Co-K催化剂合成低碳醇中的作用。Co的加入提高了催化剂合成低碳醇的活性和选择性，同时也提高了催化剂的比表面并促进了微孔的形成，催化剂的催化性能与其织构之间呈现出很好的顺变关系。Co对催化剂中可能作为合成低碳醇活性中心的低价Mo物种的电子结合能值影响较小。Co的加入降低了H2和CO在催化剂表面的强吸附中心的吸附强度，从而有利于合成低碳醇反应的发生。研究结果表明，Co仅仅是作为结构助剂，通过调变催化剂的织构和催化剂表面的H2及CO的强吸附中心而影响其合成低碳醇性能的。     

射频等离子体技术制备合成低碳醇用铜钴基催化剂

采用射频等离子体技术制备了CO加氢合成低碳醇用新型CuCo/ZrO2催化剂, 研究了等离子体气氛氮气、氢气和先氮气后氢气处理对催化剂结构和性能的影响, 并应用BET、XRD、XPS、TG和TPR技术对催化剂进行了表征. 与常规焙烧制得的样品相比, 射频等离子体技术制备的催化剂可有效抑制烃类生成, 提高总醇选择性, 大幅提高反应活性和低碳醇的时空收率. 表征结果显示, 等离子体技术使催化剂前驱体在低温下分解形成活性相, 显著提高了催化剂比表面积, 促进催化剂活性组分晶粒细化并提高其分散度, 催化剂表面的铜含量增加.     

Ce-Cu-Co/CNTs催化剂催化合成气制低碳醇及乙醇的研究

采用共浸渍法制备了不同Ce含量的Ce-Cu-Co/CNTs催化剂,考察了其在合成气制低碳醇反应中的催化性能,借助X射线衍射(XRD)、程序升温还原(H2-TPR)、N2吸脱附实验(BET)、透射电镜(TEM)和CO程序升温脱附(CO-TPD)对这些催化剂进行了表征.结果表明,当Ce的质量分数为3%时,低碳醇的时空收率和选择性达到最高,分别为696.4 mg?g-1?h-1和59.7%,其中乙醇占总醇的46.8%,适量Ce的添加能提高Cu物种在催化剂上的分散度和催化剂的还原性能,能显著地增加催化剂吸附CO的能力,促进合成醇活性位的形成,进而明显提高催化剂的活性和总醇的选择性.研究表明,将具有高活性和高碳链增长能力的CuCo基催化剂与碳纳米管的限域效应结合,可实现缩窄产物分布、大幅度提高乙醇选择性的目的.     

合成低碳醇钼系耐硫催化剂中K2CO3的作用及K^＋的结构状态

研究了合成低碳混合醇钼系耐硫催化剂的制备方法和CO加H_2反应性能。考察了K_2CO_3作为助剂对提高醇的选择性的作用。用XRD、TEM及XPS等多种测试手段分析了K~ 的结构状态,发现在催化剂表面上生成了微晶活性相。     

射频等离子体对合成低碳醇用CuCoAl催化剂的改性作用

采用共浸渍法制备了CuCo/γ-Al₂O₃催化剂,应用射频等离子体技术对催化剂进行改性处理。以CO加氢合成低碳醇为模型反应对催化剂进行活性评价,通过X射线物相分析(XRD)、氢氧滴定(HOT)、CO程序升温脱附(CO-TPD)和程序升温还原(TPR)等技术对催化剂进行表征,研究了射频等离子体技术强化处理对催化剂结构、吸附性能和还原性能的影响。结果表明,等离子体技术改性处理提高了催化剂活性组分的分散度,细化了铜物种的晶粒尺寸,增加反应活性位并调变了活性位对吸附物种的吸附强度,改进了催化剂的还原性能,等离子体改性处理的催化剂比未处理的样品CO加氢反应活性和低碳醇的时空产率显著提高。     

Synergistic effects of potassium promoter and carbon fibers on direct synthesis of isobutanol from syngas over Cu/ZnO/Al2O3 catalysts obtained from hydrotalcite-like compounds

The Cu/ZnO/Al₂O₃ catalysts (CuZnAl) can be utilized to directly synthesize higher alcohols from syngas under mild conditions. Carbon fibers (CFs) are widely used as a catalyst supporter, and potassium is usually used as a good electron assistant for charge transfer to the active phase of the catalyst. However, little is known about the combined effects of CFs and potassium on Cu/ZnO/Al₂O₃ catalysts. In this work, the CuZnAl catalysts supported on activated carbon fibers (ACFs) were prepared by a co-precipitation method, and then the catalysts were modified by potassium. The catalytic performances of K-modified CuZnAl and composites containing ACFs and CuZnAl were evaluated. Addition of ACFs and/or potassium increased CO conversion and selectivity for isobutanol compared with pure CuZnAl. All the samples were characterized by BET, XRD, SEM–EDS, CO–TPD, and Raman spectroscopy to further disclose the reason for better catalytic performance of the catalysts with ACFs and/or potassium. We found that addition of ACFs or potassium promotes moderate CO adsorption and formation of the active phase (CuO/ZnO solid solution) during alcohol synthesis, which facilitates synthesis of higher alcohols and CO conversion. As a result, ACFs and potassium exhibited synergistic effects on improvement of CO conversion and selectivity for isobutanol.     

热处理时间对CuZnAl催化剂合成C2+OH性能的影响

采用完全液相法在不同热处理时间下制备了CuZnAl催化剂,利用X射线光电子能谱（XPS）、X射线衍射（XRD）、H₂程序升温还原（H₂-TPR）、NH₃吸附-脱附（NH₃-TPD-MS）和N₂物理吸附-脱附等方法对其结构进行了表征分析,并在浆态床反应器上对其催化合成气制C₂₊OH的性能进行了研究。研究发现,延长热处理时间增强了催化剂中Cu和Al物种之间的相互作用力,改变了其中Cu⁺的量,从而影响Cu⁺-Cu⁰活性位的协同作用。同时,热处理时间的延长减少了催化剂的表面酸量,增大了孔容和孔径;催化剂表面较少的弱酸位及较大孔容和孔径均有利于C₂₊OH的生成。热处理时间为7 h时所制备的CuZnAl催化剂表现出了优良的低碳醇合成催化活性,CO转化率和总醇中C₂₊OH的质量分数分别达到了38.1%和65.9%。     

Metal dispersed activated carbon fibers and their application for removal of SOx

Uniformly metal dispersed ACFs were prepared by mixing organometallic compounds with THF and pitch. The solvent was removed from this mixture and then pitch was spun, stabilized, carbonized and activated. The specific surface areas and pore size distributions of prepared ACFs and DeSO_x catalytic reactivities were determined. The mesopores of ACF were developed by the addition of Co, Ni, Mn. The DeSO_x catalytic reactivity of Ni, Pd, Co, V and Cr dispersed ACFs demonstrated much higher continuous reaction conversion than reference pitch-ACF.     

Synthesis of Higher Alcohols via Syngas on Cu/Zn/Si Catalysts. Effect of Polyethylene Glycol Content

Cu/Zn/Si catalysts with different polyethylene glycol (PEG) content were prepared by a complete liquid-phase method, and characterized by XRD, H₂-TPR, N₂-adsorption, and XPS. The influence of PEG content on the higher alcohols synthesis from syngas was investigated. The results showed that addition of PEG can influence the texture and surface properties of the catalysts, and therefore affect their activity and product distribution. With an increase in PEG content, BET surface area, Cu crystallite size and surface active ingredient content of the catalysts first increased and then decreased, the CO conversion had similar variation tendency. However, the pore volume and pore diameter of the catalyst increased, and the binding energy of the active component and the content of Cu₂O decreased, which resulted in higher catalyst selectivity towards higher alcohols. The highest C²⁺OH selectivity in total alcohols was 60.6 wt %.     

MgZnAl hydrotalcite-like compounds preparation by a green method: effect of zinc content

A series of MgZnAl hydrotalcite-like compounds with different zinc content (1–25 mass % of nominal zinc content) were prepared by a simple and environmentally-friendly method. The solids were characterized by X-ray powder diffraction (XRD), thermogravimetric (TG), nitrogen adsorption-desorption at ?196°C (BET), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and CO₂ temperature-programmed desorption (CO₂-TPD). Transesterification of castor oil with methanol was selected as a probe reaction to stress the effect of zinc incorporation. From the XRD analysis of fresh samples it was demonstrated that the incorporation of zinc is feasible in the nominal range of 1–10 mass % while in the samples with higher zinc content, zinc nitrate and ZnO as secondary crystalline phases were observed. Furthermore, the analysis of samples calcined at 450°C indicated the coexistence of the ZnO and MgO crystalline phases. From the EDS and TG characterizations, the zinc percentage and thermal decomposition of the samples were determined. It was revealed that the samples exhibited the characteristic platy-like habit of hydrotalcite-like compounds. The BET analysis confirmed that the calcined samples presented an increment in their specific surface area values compared with the pristine ones. It was established that the amount of basic sites diminished with the zinc incorporation, which also affected the conversion degree of the transesterification reaction.     

Promoting effect of polyoxyethylene octylphenol ether on Cu/ZnO catalysts for low-temperature methanol synthesis

Cu/ZnO catalysts were prepared by the co-precipitation method with the addition of OP-10 (polyoxyethylene octylphenol ether) and were chemically and structurally characterized by means of XRD, BET, H₂-TPR, CO-TPD and N₂O-titration. The effect of OP-10 addition on the activity of Cu/ZnO for the slurry phase methanol synthesis at 150 °C was evaluated. The results showed that Cu/ZnO prepared with addition of 8% OP-10 (denoted as C8) exhibited the promoted activity for the methanol synthesis. The conversion of CO and the STY (space time yield) of methanol were 42.5% and 74.6% higher than those of Cu/ZnO prepared without addition of OP-10 (denoted as C0), respectively. The precursor of C8 contained more aurichalcite and rosasite, and the concerted effect of Cu-Zn in C8 was found to be stronger than that in C0. Compared with C0, C8 showed smaller particle size, lower reduction temperature and larger BET and Cu surface areas.     

Synthesis of Higher Alcohols from Syngas over Alkali Promoted K-Co-Mo Catalysts Supported on Multi-walled Carbon Nanotubes

A series of carbon nanotubes-supported K-Co-Mo catalysts were prepared by a sol-gel method combined with incipient wetness impregnation.The catalyst structures were characterized by X-ray diffraction,N₂ adsorption-desorption,transmission electron microscopy and H₂-TPD,and its catalytic performance toward the synthesis of higher alcohols from syngas was investigated.The as-prepared catalyst particles had a low crystallization degree and high dispersion on the outer and inner surface of CNTs.The uniform mesoporous structure of CNTs increased the diffusion rate of reactants and products,thus promoting the reaction conversion.Furthermore,the incorporation of CNTs support led to a high capability of hydrogen absorption and spillover and promoted the formation of alkyl group,which served as the key intermediate for the alcohol formation and carbon chain growth.Benefiting from these characteristics,the CNTs supported Mo-based catalyst showed the excellent catalytic performance for the higher alcohols synthesis as compared to the unsupported catalyst and activated carbon supported catalyst.     

不同载体对负载型Cu-Fe催化剂CO加氢反应性能的影响

以不同的氧化物为载体,采用共浸渍法制备了一系列负载型的Cu-Fe催化剂Cu-Fe/MO_x(MO_x=ZnO、ZrO₂、TiO₂、SiO₂、MgO、Al₂O₃),并采用X射线衍射(XRD)、N₂吸附(N₂-adsorption)、程序升温还原(H₂-TPR)和一氧化碳程序升温脱附(CO-TPD)技术对催化剂进行了表征。在温度为250℃、压力为3 MPa和原料气空速为6 000 mL/(g·h)的反应条件下,在连续流动微型固定床反应装置上考察了其催化CO加氢合成低碳醇的反应性能。结果表明,与其他氧化物为载体的催化剂相比,Cu-Fe/SiO₂催化剂表面CuO的分散度较高,在较低的温度下容易被还原,具有较强的CO吸附能力,从而同时具有较高的活性和低碳醇选择性。     

三乙醇胺改性Cu/Zn/Al类水滑石衍生氧化物催化合成气制备低碳醇

采用共沉淀法制备Cu/Zn/Al类水滑石前驱体,并用配体三乙醇胺(TEA)对其进行改性。前驱体经焙烧后成功获得TEA改性的Cu/Zn/Al催化剂。借助XRD、FTIR、H2-TPR、CO-TPD及SEM等方法对催化剂进行表征,并将其应用于合成气制备异丁醇的活性评价反应中。结果表明,TEA的加入能够改变催化剂形貌,使催化剂表面呈松散絮状结构。TEA可使类水滑石前驱体的结构发生膨胀,其焙烧获得的催化剂中有明显的晶格扭曲和晶格缺陷。TEA对催化剂结构的改变有利于Cu/Zn/Al催化剂中CuO组分的氢还原和CO在催化剂表面的化学吸附,从而促进异丁醇的合成。当TEA的添加比例为nTEA/nZn=0.5时,TEA改性的Cu/Zn/Al催化剂的催化效果达到最佳。