碳纳米管负载Cu-Co复合氧化物的富氢气氛中CO催化消除

采用超声处理辅助浸渍法制备了多壁碳纳米管负载的Cu-Co复合氧化物催化剂. 利用XRD、TEM、H₂-TPR、XPS和Raman光谱等表征了催化剂的结构性质. 在Cu和Co氧化物以及金属氧化物与碳纳米管载体间存在强相互作用. 催化剂在富氢气氛中CO催化消除反应中,与单一Cu或Co催化剂相比,Cu-Co复合氧化物催化剂表现出独特的反应特性,特别是在较高反应温度下可同时结合CO优先氧化和CO甲烷化的反应途径来实现高效CO消除. 当Cu/Co比为1/8时活性最优,可以实现在150～250 o和高反应空速 (120 L/(h·g))富氢气氛中CO的完全消除.     

助剂对Pd/γ-Al2 O3催化剂上NO选择催化还原的影响

研究了含氧条件下钯催化剂上进行丙烯选择催化还原NO的反应,考察浸渍法制备的Pd/γ-Al2O3催化剂中加入碱（土）金属或稀土氧化物助剂对NO转化率的影响,并对催化剂进行了XRD表征及在氧化气氛中饱和吸附NO后的TPD研究。结果表明,助剂CeO2、Li2O能较大幅度提高催化剂的的低温活性,使NO的最高转化率增加1-3.5倍。Pd/CeO2-Al2O3、Pd/LiO2-Al2O3催化剂有较高的Pd分散度及较强的NO解离吸附能力。并讨论了NO、N2O、NO2^-和NO3^-等吸附态物种在催化剂表面的形成及脱附特性对催化剂选择催化还原NO性能的影响。     

负载Cu的镁铝复合金属氧化物催化合成碳酸丙烯酯

通过浸渍法制备了负载Cu的镁铝水滑石类化合物Cu/HT,经过450℃焙烧得到负载Cu的镁铝复合金属氧化物Cu/LDO,利用X射线衍射(XRD)、红外光谱(FTIR)分析等技术对催化剂的结构进行了表征。研究了其对尿素与1,2-丙二醇合成碳酸丙烯酯的催化性能。考察了反应温度、反应时间、催化剂用量等工艺条件对反应性能的影响。结果表明,以水滑石为前躯体的负载Cu的镁铝复合金属氧化物cu/LDO对尿素与1,2-丙二醇合成碳酸丙烯酯具有比较好的催化活性。当反应温度为170℃、1,2-丙二醇与尿素的摩尔比为4:1、催化剂用量为原料总质量的1.0%、反应时间为3h时,碳酸丙烯酯的收率达到95.2%。     

CuO-CeO2-MnOx/γ-Al2O3催化剂选择性催化脱除NO机理研究

利用溶胶凝胶法制备CuO-CeO2-MnOx/γ-Al2O3催化剂颗粒,在固定床上测试其催化脱硝活性.CuO-CeO2-MnOx/γ-Al2O3催化剂在200～450℃范围内脱硝效率保持在70%以上.利用程序升温方法研究了催化剂对NH3的氧化性能,活性组分负载量增多,加强了催化剂对NH3氧化性能.红外表征显示NH3被吸附在催化剂的L酸位和B酸位.NO以多种硝酸盐物种在催化剂表面吸附.吸附态NH3参与SCR反应,但吸附态NO物种仅部分参加SCR反应.     

碳纳米管及其H_2吸附体系的Raman光谱

利用紫外Raman光谱技术 ,对分别以CO和CH4为碳源、由化学催化法制备的两种多壁碳纳米管以及它们的H2 吸附体系进行Raman光谱表征 ,观测到可分别归属于类石墨结构的基频模G (1 5 80cm- 1 )和D (1 41 6cm- 1 ,缺陷诱导 ) ,以及它们的二阶和三阶组合频 2D(2 83 2cm- 1 ) ,D +G (2 996cm- 1 ) ,2G (3 1 6 0cm- 1 )和 2D +G (441 2cm- 1 )的Raman峰 ;H2在这些多壁碳纳米管上吸附有两种形式 :非解离吸附分子氢H2 (a)和解离吸附生成含氢表面物种CHX(x =3 ,2 ,1 ) ,所观测在 2 85 0 ,2 96 7和 3 95 0cm- 1 处的Raman谱峰可分别归属于表面CH2 基的对称C -H伸缩模 ,CH3基的不对称C -H伸缩模 ,以及吸附态分子氢H2 (a)的H -H伸缩模     

二氧化碲(TeO2)晶体的Raman光谱研究

利用激光显微高温Raman光谱仪 ,测定了TeO2 晶体的常温Raman光谱及高温熔体法生长TeO2 晶体固 液边界层的高温Raman光谱。通过分析 ,指认了TeO2 晶体的常温Raman谱图 2 0 0～ 80 0cm- 1 谱峰的振动模式 ,解析了高温Raman谱图各谱峰的展宽、频移 ,提出了熔体可能的结构基团 ,从而为研究功能性晶体材料生长机理提供了一定依据。     

FTIR和XPS光谱分析Co—V—O催化剂的丙烷氧化脱氢活性氧物种

制备了正钒酸钴Co3 V2O8,焦钒酸钴Co2 V2O7和偏钒酸钴Cov2O6三种催化剂,进行了XRD,TEM,BET,FTLR,XPS,H2-TPR和电导等表征,并测试了他们的丙烷氧化脱氢(ODH)制丙烯催化性能.对各催化剂的FTIR主要吸收峰做了经验归属,并对其O(1s)XPS谱进行了分峰拟合,计算了催化剂表面不同氧物种的含量.制得的催化剂晶粒均匀,平均粒径为20～30 nnl,Co3 V2O8和Co2 V2O7具有p-型半导体性质,CoV2O6表现n-型半导体性质.p-型半导体Go3 V2O8和Go2 V2o7的丙烷ODH催化性能优于n-型半导体CoV2O6,当丙烷的转化率在10%时,在Co3 V2O8,Co2 V2O7,CoV2O6催化剂上丙烯选择性分别为48.12%,47.82%,35.24%.FTIR,XPS,H2-TPR和电导的研究结果表明,正、焦钒酸钴催化剂内各种价态钒之间易于进行氧化还原反应和形成氧缺位,钴含量的增加有利于丙烷转化的未充分还原的氧物种O2-,O22-,O-等增加,可以判断未充分还原的氧物种Oδ-(0＜δ＜2)是丙烷ODH活性氧物种.     

生物质基活性炭负载镍对CrⅥ的催化吸附性能研究

为了有效处理污水中的重金属铬,本文利用废弃物甘蔗渣负载镍和氮,制备出一种高催化性能的活性炭用于降解吸附污染水体中的Cr~Ⅵ.利用BET、SEM、Raman、XRD、XPS等手段对负载镍生物质基活性炭进行理化性质表征,对其催化吸附Cr~Ⅵ的性能进行评估并探究了其催化吸附机理。结果表明,在甲酸作为辅助催化剂时,负载镍生物质基活性炭对Cr~Ⅵ的最大降解量高达824.38mg/g,并且循环性能优良,活性位点有较高稳定性。而其催化吸附过程涉及到含氧官能团与Cr的络合作用、单质镍与Cr~Ⅵ氧化还原反应、Ni~(3+)和Cr~(3+)共沉淀等作用。     

基于Raman光谱的人、犬、兔血液鉴别

多物种血液鉴别对于进出口检验检疫、刑事侦检以及野生动物保护等领域尤为重要。传统的血液鉴别方法，在鉴别时常常会对血液样本造成破坏，而Raman光谱作为一种振动光谱可获得物质分子振动、转动信息，进而分析物质组成，为无损血液鉴别技术提供了可能。目前，已经有基于Raman光谱进行血液鉴别的报道，但存在如下两个问题：单一物种样本数量较少，易导致模型欠拟合；均采用线性分类模型，忽略了光谱中非线性因素的影响，降低了模型的分类性能。因此，将支持向量机沿用至Raman光谱血液鉴别中，克服了线性模型只能为光谱中线性关系建模的缺点，有效地吸收了Raman光谱中的非线性关系，实现了对人、犬及兔血液的三分类。实验通过激发波长为785 nm的海洋Raman光谱仪测得共326例样本数据(人110例、犬116例、兔100例)，利用Savitzky-Golay平滑滤波、加权最小二乘多项式拟合基线以及矢量归一化等方法对Raman光谱数据进行预处理，并选择2/3的样本数据作为校正集用于模型训练，余下1/3作为测试集用于盲测。与线性分类模型对比实验结果显示，该模型的校正集分类正确率达100%，盲测集分类正确率达93.52%，均优于线性分类模型。实验结果表明，基于支持向量机的分类模型可以用于Raman血液光谱鉴别，具有重要的研究价值和广泛的应用前景。     

Ca3NbGa3Si2O14(CNGS)晶体的拉曼光谱分析

为了研究CNGS晶体的结构,构造了Ca3NbGa2SiO12和Ca3NbGaSi2O12两个团簇模型,对其构型进行优化并计算了振动频率.利用Raman光谱技术测量了该晶体的Raman光谱,依据理论计算结果对测得的Raman光谱进行了指认,讨论了CNGS晶体的层状结构和压电性能.     

制备条件及添加稀土对SO_4~(2-)/ZrO_2-Al_2O_3固体超强酸酸性影响的研究

用共沉淀法制备了SO4 2 -/ZrO2 -Al2 O3 固体超强酸 ,并采用低温陈化和添加稀土La对其制备方法进行改进 .通过样品催化正丁烷异构化反应考察了该固体超强酸中nZr和nAl的最佳配比为 1∶2 .该法制备的样品的IR显示 ,在 1393cm-1处的吸收峰强度较常温陈化样品大大增加 .XRD分析表明 ,低温陈化和加入稀土添加剂的样品在6 5 0℃焙烧温度下 ,出现了亚稳态的ZrO2 四方晶相的晶体是表面酸性和催化活性增加的微观原因 .样品催化合成八乙酸蔗糖酯反应结果同样证明 ,在相同的时间内 ,低温陈化和添加稀土添加剂的样品具有较好的催化活性     

制备条件及添加稀土对SO42- /ZrO2 -Al2O3固体超强酸酸性影响的研究

用共沉淀法制备了SO4^2-/ZrO2-Al2O3固体超强酸，并采用低温陈化和 添加稀土La对其制备方法进行改进，通过样品催化正丁烷异构化反应考察了该固体超强酸中nZr和nAl的最佳配比为1：2，该法制备的样品的IR显示，在1393cm^-1处的吸收峰强度较常温陈化样品大大增加，XRD分析表明，低温陈化和加入稀土添加剂的样品在650℃焙烧温度下，出现了亚稳态的ZrO2四方晶相的晶体是表面酸性和催化活性增加的微观原因，样品催化合成八乙酸蔗糖酯反应结果同样证明，在相同的时间内，低温陈化和添加稀土添加剂的样品具有较好的催化活性。     

Study of nanostructured catalysts on the basis of complex oxides deposited on a carrier

A catalyst on the basis of complex oxide with perovskite structure deposited on a cellular nickel has been studied by scanning and transmission electron microscopy. The presence of the porous structure of the catalytic coating and its nature and the particle size of the catalytic phase have been established. The morphology of the intermediate layers has been studied. Such intermediate layers appearing in the case in which a secondary carrier (aluminum oxide) is used have a promoting effect on the catalyst. The regularities of the formation of ensembles of particles of the perovskite phase depending on the conditions of synthesis by pyrolysis of polymer salt compositions, such as the nature of the organic component, the ratio between the oxidant and the reductant, thermal treatment temperature have been studied.     

Effect of metal oxide and oxygen on the growth of single-walled carbon nanotubes by electric arc discharge

The effect of oxygen on the growth of single-walled carbon nanotubes was studied with Ni–Co alloy powder as catalyst under helium atmosphere of 500 Torr by electric arc discharge. The oxygen included in nickel or (and) cobalt oxides was added in catalyst. The content of oxygen in atmosphere was controlled by changing vacuum degree inside furnace before inputting buffer gas. The examinations of TEM and Raman scattering showed that oxygen in metal oxide as catalyst promotes the nucleation of SWCNT by taking effect on the metal catalyst particles. However, O₂ in atmosphere has the role of oxidizing amorphous particles along with nanotubes. When its molar proportion is higher than 0.22 ppm (Parts per million), the carbon nanotubes produced are oxidized and their purity decreases. The diameter of single-walled carbon nanotube obtained under different condition has a narrow distribution around 1.28 nm.     

Electrochemical promotion of a metal catalyst supported on a mixed-ionic conductor

It has been found that the catalytic activity and selectivity of a metal film deposited on a solid electrolyte could be enhanced dramatically and in a reversible way by applying an electrical current or potential between the metal catalyst and the counter electrode (also deposited on the electrolyte). This phenomenon is know as NEMCA [S. Bebelis, C.G. Vayenas, Journal of Catalysis, 118 (1989) 125–146.] or electrochemical promotion (EP) [J. Prichard, Nature, 343 (1990) 592.] of catalysis.Yttria-doped barium zirconate, BaZr_0.9Y_0.1O_3 − α (BZY), a known proton conductor, has been used in this study. It has been reported that proton conducting perovskites can, under the appropriate conditions, act also as oxide ion conductors. In mixed conducting systems the mechanism of conduction depends upon the gas atmosphere that to which the material is exposed. Therefore, the use of a mixed ionic (oxide ion and proton) conducting membrane as a support for a platinum catalyst may facilitate the tuning of the promotional behaviour of the catalyst by allowing the control of the conduction mechanism of the electrolyte. The conductivity of BZY under different atmospheres was measured and the presence of oxide ion conduction under the appropriate conditions was confirmed. Moreover, kinetic experiments on ethylene oxidation corroborated the findings from the conductivity measurements showing that the use of a mixed ionic conductor allows for the tuning of the reaction rate.     

钒氧化物薄膜的拉曼散射

用射频磁控溅射以纯金属钒做靶材在氩氧混合气体中制备了钒氧化物 (VO2 (B)、V6O1 3、V2 O5)薄膜。报导了钒氧化物薄膜的拉曼光谱 ,结合这些钒氧化物不同的结构特点 ,对它们的拉曼光谱进行了分类讨论     

沉淀方法及铈掺杂对铜锰氧化物催化剂催化氧化CO性能的影响

研究了铈掺杂及沉淀方法对铜锰氧化物催化剂的结构特性及室温催化氧化CO性能的影响. 使用X射线衍射、N₂吸附脱附、等离子体发射光谱、程序升温还原、紫外可见漫反射以及X射线光电子能谱等手段对各催化剂进行了表征. 发现掺杂少量的铈于铜锰氧化物催化剂中,CeO₂相高度分散并能阻止催化剂的烧结和团聚,所制得的催化剂的颗粒较小,氧化还原性能提高,比表面增大,并形成了较多的活性位点,使其对CO的催化氧化性能明显提高.     

Sonochemical preparation of carbon nanosheets supporting cuprous oxide architecture for high‐performance and non-enzymatic electrochemical sensor in biological samples

Copper (Cu) based metal oxides have high electrocatalytic ability. In this work, we are synthesized stone-like cuprous oxide particles (Cu₂O SNPs) covered on acid functionalized graphene oxide (GOS) sheets using ultrasonic process (50 kHz and 100 W). Besides, the chemical structural and crystalline analyses of Cu₂O SNPs@GOS composites were characterized by transmission electron microscopy, X-ray crystallography and energy-dispersive X-ray spectroscopy. The Cu₂O SNPs@GOS nanomaterials were tested towards detection of 8-hydroxydeoxyguanosine (8-OHdG) in biological samples. As expected Cu₂O SNPs@GOS catalyst modified electrodes performed an outstanding catalytic ability on 8-hydroxydeoxyguanosine oxidation. 8-OHdG is oxidative stress biomarker. Further, it is noted that the detection performance of Cu₂O SNPs@GOS coated electrodes and it’s highly enhanced due to the synergistic effect of Cu₂O SNPs and GOS. Besides, the modified materials provide more electro-active faces and as well as rapid electron transport pathway and shorten diffusion. Moreover, oxidation of 8-OHdG sensor is exploring a long linear or working range of 0.02–1465 µM and high sensitivity (8.75 nM). The viability of the Cu₂O SNPs@GOS proposed electrochemical methods have tested, to find out 8-OHdG concentrations in biological fluids (blood serum and urine) with a satisfying recovery ranges.     

Direct observation of p,p′‐dimercaptoazobenzene produced from p‐aminothiophenol and p‐nitrothiophenol on Cu2O nanoparticles by surface‐enhanced Raman spectroscopy

Surface‐enhanced Raman scattering of p‐aminothiophenol and p‐nitrothiophenol were obtained on the surface of Cu₂O nanoparticles, showing novel spectral changes with morphology‐dependent and time‐dependent characteristics. The measured Raman signals were believed to partly originate from the newly produced surface species p,p′‐dimercaptoazobenzene. The nature of surface chemisorption status during Raman measurement was investigated experimentally and theoretically via combined surface‐enhanced Raman scattering and density functional theory study, indicating that surface catalytic reaction of p‐aminothiophenol and p‐nitrothiophenol could take place on the surface of oxide nanostructures as well as coinage metal material. Copyright © 2013 John Wiley & Sons, Ltd.     

镧系收缩对立方Ln_2O_3Raman振动频率的影响

镧系收缩对立方Ｌｎ２Ｏ３Ｒａｍａｎ振动频率的影响薛理辉铁丽云孙育斌邓志刚林益（武汉工业大学材料研究与测试中心武汉４３００７０）ＴｈｅＤｅｐｅｎｄｅｎｃｅｏｆＲａｍａｎＶｉｂｒａｔｉｏｎａｌＦｒｅｑｕｅｎｃｉｅｓｆｏｒＣｕｂｉｃＴｙｐｅＬｎ２Ｏ３ｏｎｔ...