低碳醇合成Raney Cu—Co催化剂的研究：Ⅰ.反应性能考察

本文在５６３Ｋ、６ＭＰａ及Ｈ２／ＣＯ＝２的条件下，考察了Ｃｕ／Ｃｏ比不同的几个ＲａｎｅｙＣｕ－Ｃｏ催化剂的反应性能，结果表明：ＲａｎｅｙＣｕ－Ｃｏ催化剂上ＣＯ加氢产物主要为Ｃ１－Ｃ６正构醇及Ｃ１－Ｃ８正构烃。烃和醇产品的分布均符合Ｓｃｈｕｌｚ－Ｆｌｏｒｙ方程，但醇产品的链增长几率（０．３－０．５５）均小于烃产品的值（０．６－０．７５）。Ｃｕ／Ｃｏ比不同的催化剂在进入活性稳定区之前。均经过了一个不尽     

低碳醇合成Raney Cu－Co催化剂的研究Ⅰ．反应性能考察

本文在５６３Ｋ、６ＭＰａ及Ｈ＿２／ＣＯ＝２的条件下，考察了Ｃｕ／Ｃｏ比不同的几个ＲａｎｅｙＣｕ－Ｃｏ催化剂的反应性能。结果表明：ＲａｎｅｙＣｕ－Ｃｏ催化剂上ＣＯ加氢产物主要为Ｃ＿１－Ｃ＿６正构醇及Ｃ＿１－Ｃ＿８正构烃。烃和醇产品的分布均符合Ｓｃｈｕｌｚ－Ｆｌｏｒｙ方程。但醇产品的链增长几率（０．３－０．５５）均小于烃产品的值（０．６－０．７５）。Ｃｕ／Ｃｏ比不同的催化剂在进入活性稳定区之前，均经过了一个不尽相同的活性波动区，活性趋于稳定所需时间随Ｃｕ／Ｃｏ比增大而缩短。Ｃｕ／Ｃｏ＝０．３－１．５（原子比）时，就醇收率而言，ＲａｎｅｙＣｕ－Ｃｏ催化剂明显高于共沉淀Ｃｕ－Ｃｏ催化剂，Ｃｕ／Ｃｏ＝０．８（原子比）时，稳定醇收率达０．５７ｇ·ｇ￣（－１）·ｈ￣（－１）。     

超细Mo-Co-K催化剂合成低碳醇性能的研究

采用类凝胶法和超临界干燥技术制得超细Ｍｏ－Ｃｏ－Ｋ催化剂。研究了还原态催化剂上ＣＯ加氢合成低碳醇的反应性能,考察了不同钼钴比、钾盐助剂呈和反应条件对合成低碳醇性能的影响,在３００℃、６．０ＭＰａ,１００００ｈ＾－１的反应条件下,超细Ｍｏ－Ｃｏ－Ｋ（Ｍｏ／Ｃｏ＝７：１,Ｋ含量为１％）催化剂上低碳醇的时空产率达到６２４．４ｇ／ｋｇ－ｃａｔ．ｈ,醇选择性与４８．５％,ＯＨ／Ｃ１ＯＨ＝１．０８。     

在Zn-Cr催化剂上超临界相合成低碳醇的链增长机理

在固定床反应器中,用化学富集法研究了在Ｚｎ－Ｃｒ催化剂上超临界相合成低碳醇的链增长机理,得到超临界流体中低碳醇形成的链增长模式和产物分布方程,分析了超临界流体对低碳形成链增长的影响,结果表明,低碳醇的形成是以碳链增长的方式进行的,ＣＯＨ→ＣＣＯＨ→ＣＣＣＯＨ→ＣＣ（ＣＨ３）ＣＯＨ为低碳醇形成的机理。在链增长各步骤中,α－加成速度慢,是低碳醇形成的控制步骤,β－加成速度快,为链的增长步骤,超临界流体     

超临界相CO加氢合成甲醇,异丁醇的研究

以正十一～十三烷的混合物为超临界介质,在反应温度３６０～４１０℃、合成气压力７５ＭＰａ、进气空速１７００ｈ－１、介质压力１７８ＭＰａ、总压９３ＭＰａ的实验条件下,研究了固定床反应器中Ｚｎ－Ｃｒ、Ｃｕ－Ｚｎ－Ｃｒ催化剂在超临界相和气相条件下合成甲醇、异丁醇的性能。结果表明,超临界相反应的ＣＯ转化率高于气相反应。在超临界条件下反应,醇类选择性随着温度升高下降较慢,而气相反应醇类选择性随着温度升高下降较快。气相反应产物以甲醇、异丁醇为主,含少量乙醇和正丙醇,超临界相反应的产物分布与气相反应的明显不同,甲醇含量减少,乙醇、正丙醇和异丁醇都有不同程度增加。超临界流体的存在对合成醇链增长有影响,在不同催化剂上的产物分布有较大差异     

CuO－ZnO基CO_2／H_2合成甲醇催化剂的反应活性中心

应用ＸＰＳ，ＸＡＥＳ和紫外漫反射光谱法研究了ＣｕＯ－ＺｎＯ／氧化物上ＣＯ２／Ｈ２合成甲醇的反应活性中心．ＣｕＯ－ＺｎＯ／氧化物催化剂上的反应活性中心是存在于ＣｕＯ－ＺｎＯ固溶体中的Ｃｕ－Ｚｎ－Ｏ（＂□＂为氧空位），活性中心的Ｃｕ价态为Ｃｕ－和Ｃｕ０．反应活性中心在ＣｕＯＺｎＯ－ＺｒＯ２催化剂上比在其它ＣｕＯ－ＺｎＯ／氧化物催化剂如ＣｕＯ－ＺｎＯ，ＣｕＯ－ＺｎＯ－ＭｇＯ，ＣｕＯＺｎＯ－Ａｌ２Ｏ３和ＣｕＯ－ＺｎＯ－ｒ２Ｏ３上更加稳定．     

Cu－Co催化剂催化CO_2合成醇的原位红外表征及其反应机理

本文采用＂原位＂红外光谱结合ＸＰＳ和ＸＲＤ比较了ＣｕＣｒＫ、ＣｏＣｒＫ和ＣｕＣｏＣｒＫ三种催化剂在２．５ＭＰａ，２７０℃条件下，ＣＯ_２＋Ｈ_２合成醇的中间体及其演变过程；初步探讨了Ｃｕ－Ｃｏ催化剂中活性金属的作用、氧化物的作用、以及甲醇合成机理和碳链增长机理。研究结果表明，Ｃｕ是最主要的合成甲醇活性组分，Ｃｏ能够导致ＣＯ_２离解吸附，而碳链增长则需要二者的协同作用。吸附在金属表面的甲酸盐是甲醇合成的中间体，ＣＯ插入表面其它基团是碳链增长的关键步骤，一定量的氧化物的存在对Ｃｕ基催化剂合成甲醇活性是必不可少的，能够起到稳定表面甲酸盐的作用。     

阳离子改性HZSM-5沸石上低碳醇反应历程的TPSR-MS研究

用ＴＰＳＲ－ＭＳ技术研究了Ｃｕ，Ｚｎ和Ｇａ改性Ｈ－ＺＳＭ－５沸石的活性中心性质及Ｃ１～Ｃ４醇的反应历程。结果表明，Ｚｎ－和Ｇａ－ＺＳＭ－５有两种芳构化活性中心，即Ｂ酸和Ｚｎ，Ｇａ活性物种；甲醇在Ｃｕ－ＺＳＭ－５上只生成二甲醚、ＣＯ和ＣＯ２，而在Ｚｎ－ＺＳＭ－５上芳构化反应历程为：（１）醇经由醚脱水生成烯烃，Ｃ２～Ｃ４醇学可单分子脱水生成烯烃；（２）烯烃中间物齐聚，齐聚物通过氢转移和脱氢途径环化、芳     

不同方法制备的Cu-Co低碳醇合成催化剂的比较研究:I.吸附态CO的红外光谱

本文并行考察了用溶剂化金属原子分散（ＳＭＡＤ）、浸渍、共沉淀三种方法制备的Ｃｕ－Ｃｏ催化剂的一氧化碳加氢反应（５６３Ｋ，６ＭＰａ，Ｈ２／ＣＯ＝２）性能及附态ＣＯ的红外光谱。结果表明：（１）三种催化剂上反应产物均为Ｃ１－Ｃ５正构醇及正构烃，总醇的选择性依下列次序增：ＳＭＡＤ＜浸渍＜共沉淀。（２）表面低配位钴中心上多重吸附态ＣＯ的红外吸收峰的面积分数，对不同催化剂的变化规律，与醇选择性的变化一致；（３     

Cu—Co催化剂催化CO2合成醇的原位红外表征及其反应机理

本文采用“原位”红外光谱结合ＸＰＳ和ＸＲＤ比较了ＣｕＣｒｋ、ＣｏＣｒＫ和ＣｕＣｏＣｒＫ三种催化剂在２．５ＭＰａ，２７０℃条件下，ＣＯ２＋Ｈ２合成醇的中间体及其演变过程；初步探讨了Ｃｕ－Ｃｏ催化剂中活性金属的作用、氧化物的作用、以及甲醇合成机理和碳链增长机理。研究结果表明，Ｃｕ是最主要的合成甲醇活性组分，Ｃｏ能够导致ＣＯ２离解吸附，而碳链增长则需要二者的协同作用。吸附在金属表面的甲酸盐是甲醇合成的中     

Nanosized cobalt-based catalyst prepared by supercritical phase condition for Fischer-Tropsch synthesis

A series of nanosized Co/Zn/Mn/K composite catalysts for Fischer-Tropsch synthesis (FTS) were prepared by supercritical fluid drying (SCFD) method and common drying (CD) method. The nanosized cobalt-based catalysts were characterized by XRD, TEM and BET techniques. Their catalytic performances were tested in a slurry-bed reactor under FTS reaction conditions. The drying and crystallization were carried out simultaneously during SCFD, therefore, the catalysts prepared by SCFD method have ideal structure and show the FTS performance superior to the others prepared by CD method. The FTS activity and selectivity were improved via adding Zn, Mn and K promoters, and less CH₄ and CO₂ as well as higher yield of C₅₊ products were achieved. The optimal performance of a 92% CO conversion and a 65% C₅₊ product yield was obtained over a catalyst with the component of Co/Zn/Mn/K = 100/50/10/7. Furthermore, the catalytic performance was studied under the conditions of liquid-phase and supercritical phase slurry-bed, and C₅₊ product yield were 57.4% and 65.4%, respectively. In summary, better catalytic performance was obtained using the nanosized catalyst prepared by SCFD method under supercritical reaction conditions, resulting in higher conversion of CO, less CO₂ byproduct, and higher yield of C₅₊ products.     

助剂对Cu/Cr催化剂上甲醇部分氧化制氢的活性影响

曾研究了Cu/Cr二元催化剂上甲醇部分氧化制氢的反应，发现当Cu/Cr比为6：4时，催化剂的Cu^0比表面积最大，呈现出较好的活性。在Cu/Cr（6：4）催化剂中添加Fe,Zn,Al等8种助剂，考察其对甲醇部分氧化制氢催化性能的影响，并着重研究了Zn助剂的作用。实验结果表明，Zn的引入，有利于催化剂活性的提高。当Zn含量为10％时，催化剂活性最好。XRD表征结果表明，Cu/Cr催化剂的失活与其表面上的Cu物种烧结有关，Zn的引入可明显增强Cu/Cr（6：4）催化剂的热稳定性，提高其寿命。     

Co-doping a metal (Cr,Mn, Fe,Co, Ni,Cu, and Zn) on Mn/ZSM-5 catalyst and its effect on the catalytic reduction of nitrogen oxides with ammonia

Selective catalytic reduction (SCR) of NO_x by NH₃ over a series of Mn–M/Z catalysts (M = Cr, Mn, Fe, Co, Ni, Cu, Zn, and Z = the ZSM-5 Zeolite) synthesized by wet impregnation method was investigated. Mn–Fe/Z, Mn–Co/Z, and Mn–Cu/Z catalysts exhibited approximately 100 % NO_x conversion over a wide temperature range (200–360 °C) in a defined atmospheric condition, which was noticeably greater than that of Mn–Cr/Z (340–360 °C). Furthermore, the effect of addition of second metal oxide species to the initial Mn/Z catalyst on the structure of catalysts was studied by several characterization techniques. BET measurements revealed high surface area and pore volume of the Mn–Cu/Z catalyst. In addition, the XRD and UV–Vis DR results showed that addition of co-doped metal oxide species improved the dispersion of metal ions and inhibited crystallization of metal oxides. UV–Vis studies also were in good accordance with DTA/TG results confirming the formation of cobalt oxide and copper oxide clusters in Mn–Co/Z and Mn–Cu/Z catalysts, respectively. The FTIR spectra of pyridine adsorption, in addition, suggested the Mn–Cu/Z catalyst contained the most Lewis acid sites leading to more NO_x adsorption capacity.     

在超临界正己烷介质中的F-T合成反应行为

在固定床反应器中,以正己烷为超临界介质,研究了三种Co催化剂（浸渍、喷雾干燥、双模催化剂）上的F-T合成反应行为。在相同的Co质量分数下,喷雾干燥催化剂和双模催化剂的活性接近,都高于浸渍催化剂。在喷雾干燥催化剂上CO的转化率显著高于浸渍催化剂。喷雾干燥催化剂F-T产物中具有高的低碳选择性和低的1-烯烃质量分数,然而在相近的CO转化率下,喷雾干燥和浸渍催化剂具有类似的1-烯烃质量分数。对于浸渍催化剂,当Co质量分数从5％增加到15％,CO转化率从8.3％增加到43.6％。含Co5％的催化剂比质量分数为10％、15％、20％催化剂的甲烷选择性低2.0%～3.0%,但产物中1-烯烃的质量分数明显要高。     

丙烷氧化脱氢M-Fe-O催化剂的研究

采用微波加热草酸盐共沉淀法制备了一系列M-Fe-O(M=V、Cr、Mn、Co、Ni、Cu、Zn)催化剂,考察了其对丙烷氧化脱氢制丙烯反应的催化性能,并对催化剂进行了BET、XRD、H2-TPR、电导测量等表征.实验结果表明V-Fe-O和Cr-Fe-O催化剂表现出较好的丙烷氧化脱氢制丙烯催化性能.反应温度为873 K时,以V-Fe-O为催化剂时丙烷转化率34.46%,丙烯选择性30.91%;在Cr-Fe-O为催化剂上丙烷转化率36.31%,丙烯选择性34.22%.     

改性SiO2对铁基催化剂H2、CO吸附及加氢性能的影响

采用溶胶凝胶方法通过掺杂修饰剂M（M=Mn、Zn、Zr、Sr）制备出改性SiO₂载体,再用浸渍法将Fe元素负载于该载体上制成系列催化剂。采用X射线衍射（XRD）、氮气物理吸附-脱附、X射线光电子能谱（XPS）等手段表征了催化剂的织构性质、晶相组成和电子性质。利用程序升温手段研究了催化剂的H₂还原吸附性质和CO加氢性能。借助动力学分析方法研究了催化剂与H之间的相互作用。结果表明,少量掺杂的修饰剂对催化剂的Fe物相组成以及表面Fe物种电子状态基本没有影响,但降低了催化剂的比表面积以及活性相分散度,削弱了对H₂的吸附能力,降低催化剂的H₂脱附活化能。Zn、Zr的掺杂抑制了催化剂的还原,而Mn、Sr的掺杂却促进催化剂的还原。Mn、Zn、Zr的掺杂抑制催化剂表面CO的解离吸附,Sr则促进CO的解离吸附,Mn、Zn、Zr、Sr均促进低温区间C-C耦合和加氢反应,其中,Mn、Zr促进加氢的作用更显著。     

Cu/Zn、Cu/Zn/Ni催化剂甲醇部分氧化制氢

研究了甲醇在Cu/Zn及Cu/Zn/Ni催化剂上部分氧化热耦合裂解制氢的反应,系 统地考察了不同O2/CH3OH比及反应温度下催化剂性能.当O2/CH3OH=0.2时,催化剂的性能最 佳.在同样条件下, Cu/Zn催化剂对CO的选择性较Cu/Zn/Ni催化剂低,更具优势. Cu/Zn催化 剂用于甲醇部分氧化反应时,甲醇转化率在150 h寿命实验中基本保持在90％左右. XRD谱图 表明Cu/Zn合金的生成是导致Cu/Zn系催化剂在甲醇裂解反应中快速失活的主要原因,而在部 分氧化反应中, O2的存在可抑制Cu/Zn合金的生成,使Cu/Zn催化剂表现出高度的稳定性.     

Catalytic Gas‐phase Fluorination of Hexachlorobutadiene to 1,2‐Dichlorotetrafluorocyclobutene over Cr/Zn‐based Catalysts

In this paper, the gas‐phase fluorination of hexachlorobutadiene (HCBD) to synthesize 1,2‐dichlorotetrafluorocyclobutene (DTB) was carried out over a series of Cr/M/Zn catalysts (M = Ni, Co, Cu, In, Al). The influence of prefluorination by different fluorinating agents (HF, 95%HF + 5%Cl₂, 95%HF + 5%O₂, CF₂O, CF₂Cl₂) on catalytic performance of Cr/Co/Zn sample was also investigated. The addition of prompters to the Cr/Zn catalyst improved remarkably its catalytic properties. The Cr/Ni/Zn catalyst exhibited the best catalytic activity (1.318 mmol/h/g) at 390 °C and the Cr/Co/Zn catalyst showed the best DTB selectivity (42.5%) at 350 °C. Compared to that of gaseous HF, the catalytic performance of the Cr/Co/Zn catalyst after treatment by HF + O₂ and CF₂O increased considerably, whereas for HF + Cl₂ and CF₂Cl₂ it showed little effect. In order to identify the different species (Cr─O, Cr─F, CrO _xF _y) present on catalysts’ surface and determine their exact role, these catalysts before and after the reaction were characterized by X‐ray photoelectron spectroscopy. It was found that the concentration of the various species was responsible for the activity and lifetime of catalysts. Moreover, a possible reaction route is proposed based upon the product distribution. The most feasible formation pathway of DTB proceeded via the cyclization of C₄Cl₄F₂ or C₄Cl₃F₃ to yield c‐C₄Cl₄F₂ and c‐C₄Cl₃F₃ followed by further the Cl/F exchange.     

甲烷部分氧化制合成气Ⅱ．镍系催化剂的反应性能

主要用第四周期金属元素的氧化物与Ａｌ２Ｏ３的复合氧化物催化剂上甲烷氧化的结果证实了催化剂设计中的预测：（１）催化剂首先应能解离活化甲烷，（２）催化剂要能较快地活化Ｏ２分子．只有同时满足这两个条件，催化剂才可能有较好的甲烷部分氧化活性．第四周期元素中只有镍具有这样的性质．Ｃｕ，Ｍｎ，Ｃｒ，Ｌａ，Ｃａ，Ｚｎ等氧化物的添加可明显提高Ｎｉ－Ａｌ２Ｏ３催化剂的甲烷部分氧化性能，其中Ｃｕ的助催化性能最好．催化剂ＮｉＯ－ＣｕＯ－Ａｌ２Ｏ３，ＮｉＯ－ＭｎＯ－Ａｌ２Ｏ３，ＮｉＯ－Ｃｒ２Ｏ３－Ａｌ２Ｏ３的反应活性和选择性顺序，与金属Ｃｕ，Ｍｎ，Ｃｒ上ＣＯ和Ｈ２脱附的顺序是一致的     

Metal oxide promoted TiO2 catalysts for photo-assisted selective catalytic reduction of NO with NH3

The photo-assisted selective catalytic reduction (SCR) of NO with NH₃ (Photo-SCR) was performed over TiO₂ modified by supporting 1 wt% of various transition metal (V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ta or W) oxides aiming at the improvement of the photo-SCR activity. The addition of Nb, Mo or W oxide to TiO₂ was found to enhance the photo-SCR activity. We have reported that the amount of acid sites on TiO₂ is one of the key factors to the photo-SCR activity. The increase in the activity depends on the enhancement of acidity of catalyst by the addition of Nb, Mo or W oxide. In contrast, the addition of V, Cr, Mn, Fe, Co, Ni or Cu oxide to TiO₂ lowered the photo-SCR activity, although addition of metal cations also changed the acidity of TiO₂. We guess that the reduction of the activity was caused by two reasons; the first is that the sites newly formed on these transition metal oxides is not photoactive and the second is that TiO₂ supporting V, Cr, Mn, Fe, Co, Ni or Cu oxides had low stabilities under the reaction conditions, i.e., the chemical state of the cations changed during the reaction. Therefore, we concluded that the increase in the acid sites that are active sites for photo-SCR and the stability of the catalysts are important for the photo-SCR.