Higher alcohol synthesis over Cu-Fe composite oxides with high selectivity to C_(2+)OH

Cu-Fe composite oxides were prepared by co-precipitation method and tested for higher alcohol synthesis from syngas. The selectivity to C2＋OH and C6＋OH in alcohol distribution was very high while the methane product fraction in hydrocarbon distribution was rather low, demonstrating a promising potential in higher alcohols synthesis from syngas. The distribution of alcohols and hydrocarbons approximately obeyed Anderson-Schulz-Flory distribution with similar chain growth probability, indicating alcohols and hydrocarbons derived from the same intermediates. The effects of Cu/Fe molar ratio, reaction temperature and gas hourly space velocity （GHSV） on catalytic performance were studied in detail. The sample with a Cu/Fe molar ratio of 10/1 exhibited the best catalytic performance. Higher reaction temperature accelerated water-gas-shift reaction and led to lower total alcohols selectivity. GHSV showed great effect on catalytic performance and higher GHSV increased the total alcohol selectivity, indicating there existed visible dehydration reaction of alcohol into hydrocarbon.

Enhanced selective catalytic reduction of NO with NH3 via porous micro-spherical aggregates of Mn–Ce–Fe–Ti mixed oxide nanoparticles

We rationally designed a high performance denitration(De-NOx) catalyst based on a micrometer-sized spherical Mn–Ce–Fe–Ti(CP-SD)catalyst for selective catalytic reduction(SCR). This was prepared by a co-precipitation and spray drying(CP-SD) method. The catalyst was systematically characterized, and its morphological structure and surface properties were identified. Compare with conventional Mn–Ce–Fe–Ti(CP) catalysts, the Mn–Ce–Fe–Ti(CP-SD) catalyst had superior surface-adsorbed oxygen leading to enhanced 'fast NH3-SCR' reaction. The asobtained Mn–Ce–Fe–Ti(CP-SD) catalyst offered excellent NO conversion and N2 selectivity of 100.0% and 84.8% at 250℃, respectively, with a gas hourly space velocity(GHSV) of 40,000 h-1. The porous micro-spherical structure provides a larger surface area and more active sites to adsorb and activate the reaction gases. In addition, the uniform distribution and strong interaction of manganese, iron, cerium, and titanium oxide species improved H2O and SO2 resistance. The results showed that the Mn–Ce–Fe–Ti(CP-SD) catalyst could be used prospectively as a denitration(De-NOx) catalyst.

Preparation and characterization of Cu-Ce-La mixed oxide as water-gas shift catalyst for fuel cells application

Cu-Ce-La mixed oxides were prepared by three precipitation methods （coprecipitation, homogeneous precipitation, and deposition precipitation） with variable precipitators and characterized using X-ray diffraction, BET, temperature-programmed reduction, and catalytic reaction for the water-gas shift. The Cu-Ce-La mixed oxide prepared by coprecipitation method with NaOH as precipitator presented the highest activity and thermal stability. Copper ion substituted quadrevalent ceria entered CeO2 （111） framework was in favor of activity and thermal stability of catalyst. The crystallinity of fresh catalysts increased with the reduction process. La^3＋ or Ce^4＋ substituted copper ion entered the CeO2 framework during reduction process. The coexistence of surface copper oxide （crystalline） and pure bulk crystalline copper oxide both contributed to the high activity and thermal stability of Cu-Ce-La mixes oxide catalyst.

Cu对Fe基催化剂NH_(3)-SCR性能助力作用研究

Fe基催化剂在中温范围有着良好的催化活性,而Cu基催化剂有着低温优势,因此将两者相结合,采用表面活性剂辅助法制备了Fe-Cu复合氧化物.引入Cu后,Fe-Cu催化剂的NO x转化率达90%,起燃温度下降至150℃.Fe_(2)O_(3)和CuO之间的相互作用使得催化剂的比表面积增大约1/4,且增强了Fe^(3+)的亲电性,促进NO_(2)等电负性物质的吸附.同时提高了催化剂的氧化还原能力与表面吸附氧Oα比例,NO更易向NO_(2)转变,快速SCR(选择性催化还原)进程更易发生.此外,Fe_(2)O_(3)和CuO的相互作用让催化剂拥有较多的酸性位点,有利于催化活性的提升.最终使得Fe-Cu催化剂不仅继承了Cu基催化剂的低温优势,还保持了优良的N_(2)选择性.

Novel-structured Mo-Cu-Fe-O composite for catalytic air oxidation of dye-containing wastewater under ambient temperature and pressure

A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐programmed reduction by H2,cyclic voltammetry,and temperature‐programmed desorption by O2.The results showed that Mo6+diffused into the Cu‐Fe‐O crystal lattice and then formed a new crystalline phase of CuMoO4.The Mo‐Cu‐Fe‐O catalyst had redox properties,and its surface contained active sites for oxygen adsorption.In addition,the catalytic activity of the Mo‐Cu‐Fe‐O composite was evaluated by the degradation of Cationic Red GTL,Crystal Violet,and Acid Red in catalytic wet air oxidation(CWAO)at ambient temperature and pressure.The Mo‐Cu‐Fe‐O catalyst showed excellent activity at basic conditions for the degradation of Cationic Red GTL.High removal efficiencies of91.5%and92.8%were achieved for Cationic Red GTL and Crystal Violet,respectively,in wastewater,and the efficiency remained high after seven cycles.However,almost no degradation of Acid Red occurred in the CWAO process.Furthermore,hydroxyl radicals were formed in the CWAO process,which induced the decomposition of the two cationic dyes in wastewater,and the toxicity of their effluents was decreased after degradation.The results indicate that the Mo‐Cu‐Fe‐O composite shows excellent catalytic activity for the treatment of wastewater contaminated with cationic dyes.

Enhanced catalytic performance of Cu-and/or Mn-loaded Fe-Sep catalysts for the oxidation of CO and ethyl acetate

The Fe-modi fied sepiolite-supported Mn–Cu mixed oxide(Cux Mny/Fe-Sep) catalysts were prepared using the co-precipitation method.These materials were characterized by means of the XRD,N_2 adsorption–desorption,XPS,H_2-TPR,and O_2-TPD techniques,and their catalytic activities for CO and ethyl acetate oxidation were evaluated.The results show that catalytic activities of the Cux Mny/Fe-Sep samples were higher than those of the Cu1/Fe-Sep and Mn2/Fe-Sep samples,and the Mn/Cu molar ratio had a distinct in fluence on catalytic activity of the sample.Among the Cux Mny/Fe-Sep and Cu1Mn2/Sep samples,Cu1Mn2/Fe-Sep performed the best for CO and ethyl acetate oxidation,showing the highest reaction rate and the lowest T50 and T90 of 4.4×10^(-6) mmol·g-1·s-1,110,and 140 °C for CO oxidation,and 1.9×10^(-6) mmol·g-1·s-1,170,and210 °C for ethyl acetate oxidation,respectively.Moreover,the Cu1Mn2/Fe-Sep sample possessed the best lowtemperature reducibility and the lowest temperature of oxygen desorption as well as the highest surface Mn^(4+)/Mn^(3+) and Cu^(2+)/CuO atomic ratios.It is concluded that factors,such as the strong interaction between the Cu or Mn and the Fe-Sep support,good low-temperature reducibility,and good mobility of chemisorbed oxygen species,might account for the excellent catalytic activity of Cu1Mn2/Fe-Sep.

Formation and Oxidation Behavior of Al-Cu-Fe Quasicrystal

Al62.5Cu25Fe12.5 alloy was prepared by arc melting. It was found that the formation of quasicrystalline phase is related to the condition of annealing, such as temperature and duration. Weight gain of AI-Cu-Fe quasicrystal during the oxidation at 700 and 800℃ in dry air was measured by means of thermal balance. The oxidation kinetics showed that the quasicrystal has good oxidation resistance. Only α-Al2O3 was formed on Al62.5Cu25Fe12.5 quasicrystal. The surface morphologies of AI-Cu-Fe quasicrystal after isothermal oxidation for different times were observed.

Electrodeposited Ni,Fe,Co and Cu single and multilayer nanowire arrays on anodic aluminum oxide template

The Ni, Fe, Co and Cu single and multilayer nanowire arrays to make perpendicular magnetic recording media were fabricated with nanoporous anodic aluminum oxide (AAO) templates from Watt solution and additives by the DC electrodeposition. The results show that the diameters of Ni, Fe, Co and Cu single and multilayer nanowires in AAO templates are 40-80 nm and the lengths are about 30 μm with the aspect ratio of 350-750. The magnetic properties of the prepared nanowires are different under different electrodepositing conditions. The remanences (Br) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires, and coercivity (Hc) of Ni/Cu/Fe multilayer nanowires are lower than those of others multilayer nanowires. These are compatible with the required conditions of high density magnetic media devices that should have the low coercivity to easily success magnetization and high remanence to keep magnetization after removal of magnetic field.

Oxidation of two ternary Fe-Cu-5Al alloys in 1×10^5 Pa pure oxygen at 700℃

The oxidation of two two-phase ternary Fe-Cu-Al alloys containing about 5% Al(mole fraction), one Fe-rich and one Cu-rich, were studied at 700℃in 1×105 Pa pure oxygen. The Fe-rich alloy (Fe-15Cu-5Al) shows two quasi-parabolic stages, with a large increase of the parabolic rate constant after about 4 h. The presence of 5% Al does not change greatly the oxidation rate of Fe-15Cu-5Al with respect to a binary Fe-Cu alloy of similar composition, which was quite different from the situation of the same alloys oxidized at 800℃. Oxidation of Fe-15Cu-5Al at 700℃produced an outer layer of iron oxides and an inner layer containing a mixture of copper metal, iron and aluminium oxide. On the contrary, the Cu-rich Fe-85Cu-5Al alloy presents a rather irregular kinetic behavior, with formation of an inner continuous alumina thin layer and a rather irregular outer layer. The outer layer with a rather irregular thickness was mainly composed of a matrix of copper oxides plus some aluminium and iron oxides presenting in the deep part of the layer at certain locations. As a result of the formation of a protective alumina layer, the presence of 5% Al greatly reduced the oxidation rate of Fe-85Cu-5Al with respect to a binary Fe-Cu alloy of similar composition, which was also quite different from the situation of the same alloys oxidized at 800℃. Moreover, the oxidation rate at 700℃of the Fe-85Cu-5Al alloy was much lower than that of Fe-15Cu-5Al alloy due to the same reason..

Development and Oxidation Behavior of Al-Cu-Fe Quasicrystalline Coating on Ti Alloy

An oxidation resistant Al-Cu-Fe quasicrystalline coating was fabricated on substrate of Ti alloy by low pressure plasma spraying (LPPS) method. As-sprayed Al-Cu-Fe coating has a rapidly solidified lamellar microstructure consisting of quasicrystalline phase and crystalline phase. The formation of quasicrystalline coating is related to the annealing. The results from the ox!dat!on experiments showed that Al-Cu-Fe quasicrystalline coating improved the oxidation resistance of Ti-base alloys. During the oxidation period there is no evident spallation of the coating from the substrate. Oxide formed on the surface of Al-Cu-Fe quasicrystalline coating after oxidation consisted of Al2O3. Oxidation occurs Ieading to a change of concentration and phase transformation in the coating surface. Selective oxidation of AI transforms the quasicrystalline phase into the phase.

非均相UV/Fe-Cu-Mn-Y/H_2O_2反应催化降解4BS染料废水

制备了负载在Na Y分子筛上的Fe Cu Mn Y复合催化剂,并对其在非均相UV Fe Cu Mn Y H2O2体系中催化氧化4BS染料废水进行了研究.结果表明,非均相UV Fe Cu Mn Y H2O2体系对4BS染料废水的处理具有很高的效率.在基准条件下,反应时间为20min时,废水中4BS的去除率达到了93 7%.与均相UV Fenton体系不同,非均相UV Fe Cu Mn Y H2O2体系在碱性条件下(pH=10 5)仍可高效去除CODCr.动力学研究得到催化氧化4BS废水的模型方程,该模型可以为非均相UV Fe Cu Mn Y H2O2体系处理高色度的实际染料废水提供指导.

Fe-Cu混合氧化物催化湿式氧化低浓度磷化氢实验研究

采用催化湿式氧化法对低浓度磷化氢净化进行实验研究,制备铁、铜单体催化剂以及Fe-Cu混合氧化物催化剂和Fe-Cu-Ce混合氧化物催化剂。研究反应温度和气体流量对磷化氢净化效率的影响。实验结果表明:当反应温度为50℃,气体流量为200mL/min,氧气浓度为0.5%～3.0%,磷化氢入口质量浓度为0.8～1.0g/m3时,以Fe-Cu混合氧化物作催化剂,磷化氢的净化效率达到70%;当加入稀土元素铈对催化剂进行改性后,净化效率提高到76%,且催化剂的稳定性增强;当温度较高、气体流速较低时,净化效率较高;低浓度磷化氢可以用催化湿式氧化法来脱除。

Fe、Co组成对Cu-Fe-Co基混合醇催化剂合成性能的影响

采用共浸渍法制备了一系列不同Fe、Co组成的Cu-Fe-Co基混合醇催化剂,对其CO加氢合成混合醇反应性能进行了考察,并采用BET比表面积分析、X射线衍射(XRD)、X射线光电子能谱(XPS)、场发射扫描电子显微镜(FE-SEM)及H_2程序升温还原(H_2-TPR)等手段对其进行了表征.结果表明:Cu-Fe二元催化剂添加适量的Co可以明显提高催化剂醇的明空收率(STY)、CO转化率,而总醇选择性不变.当活性组分Cu、Fe及助剂Co的质量分数分别为25%、22%、3%时,催化剂醇的时空收率高达205.6 g·kg^(-1)·h^(-1),CO转化率为56.6%.XRD、XPS和TPR结果表明:在Cu组分含量不变时,少量Co组分的引入使催化剂表面形成微量的CuFe_2O_4相,促进了Cu-Fe组分间相互作用的增强,改善了催化剂活性组分的分散度,有利于提高催化剂活性及醇的时空收率;随Co含量的增大,催化剂中金属组分间的相互作用发生转变,形成了Cu-Co尖晶石相,导致催化剂的醇选择性有所下降.

Fe/Cu体系湿式催化氧化一步高效脱除H_2S新方法研究

提出了Fe Cu体系室温湿式催化氧化一步高效脱除H2 S废气的新方法 ,阐述了反应机理、实验装置和工艺流程 ;考察了Fe3+ 、Cu2 + 浓度和H2 S入口浓度对H2 S脱除效率的影响及Fe3+ 、H+ 与添加剂NaCl浓度对CuS氧化浸出的影响 ,分析了Fe3+ 、Cu2 + 、H+ 浓度和废气中O2 含量对Fe3+ 、Cu2 + 再生的影响 ;并进行了综合实验 .结果表明 ,当废气中O2 体积分数为 5 %时 ,新方法中含 40g·L- 1 Cu2 + 及 80g·L- 1 Fe3+ 的吸收体系即能对体积分数为 10 0 0× 10 - 6 的H2 S废气 10 0 %稳定脱硫 ,体系除消耗O2 外 ,过程不消耗任何原料 ,不产生二次污染 。

Ni-Fe-Cu惰性金属阳极的抗氧化和耐蚀性能

对Ni Fe Cu合金的抗氧化和耐熔盐腐蚀性能进行了研究。结果显示,该合金的氧化动力学曲线符合抛物线规则。静态电解质中的溶解腐蚀速率随温度的增高和NaF与AlF3的摩尔分子比的降低而增大。在不同电解条件下,组成为NaF AlF3 NaCl CaF2 Al2O3的电解质体系中电解时,该阳极周围产生大量气泡,槽电压在3.6～4.2之间波动,阳极的电解极化腐蚀速率随电解质中氧化铝浓度的增高、温度的降低而减小,产品铝的纯度达到97%～98%。

Cu-Fe-Ru-La/γ-Al_2O_3湿式氧化催化剂的制备、表征及机理(英文)

采用等量浸渍法以γ-Al2O3为载体,制备过渡金属Cu和Fe、贵金属Ru、稀土金属La的复合催化剂。采用催化湿式空气氧化法处理模拟印染废水,研究金属离子配比、焙烧温度对催化剂活性及稳定性的影响,并对催化剂CWAO反应机理进行探讨:权衡催化剂的活性和稳定性,催化剂的组分质量配比和焙烧温度分别为Cu∶Fe∶Ru∶La=1∶1∶1∶3、450℃。对催化剂进行XRD、XPS、孔结构、FT-IR、TG-DTA、SEM、TEM表征,结果表明:焙烧使催化剂组成物质分解为氧化物,元素Cu、Fe、Ru、La分别以CuO、Fe2O3、RuO2、La2O3形式存在;焙烧温度升高,晶粒长大结晶趋于完整,催化剂孔容孔径增大但比表面积减小,晶粒尺寸分布在5～20 nm;Cu-Fe-Ru-La/γ-Al2O3催化剂使用前后结构无明显变化且反应后溶出的金属浓度低,催化剂具有较高的稳定性。

三元Cu—Ni—Fe合金在700—900℃空气中的氧化

研究了三元双相 Ｃｕ—３０Ｎｉ—２５Ｆｅ合金在 ７００—９００℃空气中的氧化在相同温度下合金的氧化速率都低于纯铜的，７００—８００℃的氧化动力学为抛物线规律，在９００℃初期为抛物线规律，后期变为线形规律，氧化膜最外层为近乎纯的氧化铜；内层是由三种金属组元的氧化物及组无间的复合氧化物所构成的混合区域，另外，在外氧化膜下面发生了Ｆｅ和Ｎｉ的内氧化，而内氧化区前沿的合金中仍保持为双相结构，该合金中难以发生Ｆｅ的选择性外氧化，这是组元间较小互溶度及合金双相结构限制了Ｆｅ的扩散的结果．

Fe-Cu纳米涂层在700与800℃空气中的氧化

利用磁控溅射技术制备了Ｆｅ含量（质量分数，％）分别为２５和５０的两种Ｆｅ－Ｃｕ纳米涂层，并研究了该涂层在７００与 ８００ ℃空气中的氧化结果表明， Ｆｅ—７５Ｃｕ涂层氧化后形成了外层为氧化铜和内侧为氧化铁的复合氧化膜，而 Ｆｅ—５０Ｃｕ发生了 Ｆｅ的单一外氧化，其氧化特征均有别于同成分的铸态合金这种氧化机制在于晶粒尺寸细化显著扩展了 Ｆｅ在 Ｃｕ中的溶解度，同时大量的晶界也为组元扩散提供了短路通道。

Ni-Cu-Fe-Al合金在850℃空气中的氧化行为

为研发铝电解惰性阳极连接导杆新材料,采用粉末冶金法制备Ni-Cu-Fe-Al四元合金,在850℃的空气气氛中进行氧化实验,并用XRD、SEM、EDS等测试设备对其表面氧化膜的成分、形貌和组成进行分析。结果表明,在该合金表面形成的氧化膜连续、致密,分为内、中、外三层,外层以铜镍复合氧化膜为主,中间层分布着岛状的铁氧化物,其中含有一定数量的NiFe2O4尖晶石相,内层为连续致密的Al2O3膜,能阻碍元素扩散,从而有效提高合金的高温抗氧化性能。

Cu/Co/Fe水滑石衍生的复合氧化物催化高氯酸铵热分解的研究(英文)

以Cu／C0／Fe水滑石（Cu／Co／Fe-LDHs）为前驱体经过焙烧制备了Cu／Co／Fe复合氧化物fCu／C0／Fe．MOs）。利用DTA和TG-MS研究了Cu／Co／Fe—MOs作为新型催化剂对高氯酸铵热分解的催化性能。结果表明，Cu／Co／Fe．MOs呈现为CuFe2O4和（CoFe2）O。晶相，具有70～110m2·g-1。的比表面积。晶粒大小均匀，尺寸在20—30nm。添加4wt％的400℃焙烧得到的Cu／Co／Fe—MOs催化剂使高氯酸铵热分解反应的温度降低了139℃。Cu／C0／Fe．MOs是通过吸附在金属氧化物表面的超氧离子（O2-）来加速高氯酸铵热分解的。