Preparation of Supported Palladium Catalyst by Bioreduction

［中文文摘］将微生物可在常温下还原贵金属离子的特性引入催化剂的制备过程中,利用对Pd2+具有较强还原能力的地衣芽孢杆菌(简称R08)制得负载型Pd催化剂(简称催化剂)。采用X射线光电子能谱(XPS)和透射电镜(TEM)对催化剂进行表征。XPS测定结果表明,室温下R08菌体可将γ-A l2O3载体表面上的Pd2+基本还原为Pd0;生物还原法制得的催化剂的Pd微粒的平均粒径约为5nm。将该催化剂用于2%CO-98%空气(体积分数)混合气的催化氧化反应,CO完全氧化的最低反应温度为60℃,在此温度下催化剂的活性可恒定150h,结果优于相同条件下化学浸渍法制得的催化剂。XPS表征和催化活性评价结果说明,用于CO催化氧化反应的催化剂中单原子Pd活性中心的价态为0~+2。［英文文摘］Pd catalyst supported on γ2a lumina ( nanoparticles) with high dispersion was prepared by bioreduction with Bacillus lichenifoum is ( strain R08) , which was strong in reducing ab ility of Pd2 + . Catalysts prepared by bioreduction and impregnation were cha racte rized by m eans of XPS and TEM.XPS spectra indicated tha t s train R08 could almost completely reduce Pd2 + to Pd0. TEM images showed that average sizes of Pd particles on catalysts prepared by bioreduction and by impregnation were 5 nm and 18 nm, respectively. When catalyst p rep ared by bioreduc tion w as used in ox idization of carbon m onoxide to carbon dioxide, the carbon monoxide could be comp letely oxidized at the lowest temperature of 60 ℃and activity of catalyst could be main tained a t this tempe rature fo r 150 h. The result was better than catalyst prepared by imp regnation. Pd ( Ph2 PCH2 PPh2 ) 2 suppo rted on γ2alum ina was synthesized as catalyst for the oxidation. Results of XPS spectra and activity eva luation indicated that chemical valence state of Pd on active center of catalyst was between 0 and + 2.国家自然科学基金项目(20376067

聚酰胺硅胶吸附茶多酚的红外光谱研究

IR谱表明:聚酰胺硅胶吸附剂中,聚酰胺的N—H和硅胶表面OH以氢键结合,υC=O无位移;室温下该吸附剂中C=O和茶多酚中O—H作用后,υC=O和υO—H分别红移了11cm-1和18cm-1;而与咖啡因及氨基酸作用后υC=O无位移

Temperature Programmed Decomposition of NO over Er 2O 3/Bi 2O 3 Catalysts

nOX是造成大气污染的化学物质之一，因此，消除nOX是环境保护的一项重要任务.目前比较成熟的消除nOX工艺是用氨为还原剂和V2O5/TIO2为催化剂的选择催化还原（SCr）法［1］，但其成本过高.其后发展了用CH4等低碳烷烃作还原剂，在O2共存下用C...The Face centered cubic(Fcc) phases of n (Er 2O 3)/ n (Bi 2O 3)=5%￣40%, molar Fraction) which is an oxygen ion conductor were prepared.The decomposition of NO over these Er 2O 3/Bi 2O 3 catalysts was examined by means of temperature programmed surFace reaction.The results showed that the surFace adsorbed NO decomposed to N 2 and O 2 at ca.600 ℃.The plot of NO conversion and Er composition showed that there was an optimum decomposition rate at ca.23%(molar Fraction).Comparing to the data of conductivity, one can conclude that the rate of NO decomposition increases with the increase in the number of oxygen vacancies.This has been contributed to the similar electronic structure between O 2 and NO.国家自然科学基金;香港研究基

提高CO_2加氢合成甲醇选择性和收率的一种方法

提高CO2加氢合成甲醇选择性和收率的一种方法李基涛张伟德付金印古萍英（厦门大学化学系物理化学研究所361005）区泽棠（香港浸会大学化学系九龙塘）关键词CO2加氢合成甲醇CO的作用提高选择性和收率随着工业发展和人类利用石化能源的增加，大气中CO2浓度...香港浸会大学科研基金;厦门大学固体表面物理化学国家重点实验

Catalytic Oxidative Dehydrogenation of Propaneand Isobutane over Rare Earth Oxyfluorides

稀土氟氧化物在丙烷、异丁烷氧化脱氢中的催化作用张伟德＊洪碧凤古萍英万惠霖蔡启瑞（厦门大学化学系，固体表面物理化学国家重点实验室，物理化学研究所厦门361005）关键词丙烷，异丁烷，催化氧化脱氢，稀土氟氧化物1997-10-06收稿，1998-01-0...Three rare earth oxyfluorides Sm2O3/4CeF3, Nd2O3/4CeF3 and Y2O3/4CeF3 were prepared.They were active in oxidative dehydrogenation of propane and isobutane with high selectivity to propene and isobutene.The propane is easier to dehydrogenate than isobtuane, and the isobutane is easier to crack.XRD measurements indicated the existence of new phase such as CeO2 and REF3 or REof as a result of the exchange between F- and O2- during the preparation.The insitu Raman spectra implied that O-2 was the active species.国家自然科学基

V_2O_5/MPO_4在丙烷氧化脱氢中的催化作用

研制了具有不同酸碱性的磷酸盐ＭＰＯ４（Ｍ＝Ａｌ，Ｚｒ，Ｃａ）载体，并用这些载体负载０６％～６０％的Ｖ２Ｏ５。所制备的催化剂在丙烷氧化脱氢反应中具有较好的催化性能，如３％Ｖ２Ｏ５／Ｃａ３（ＰＯ４）２催化剂在丙烷转化率为１７０％时，丙烯选择性可达５５９％，丙烯收率达９５％。考察了不同反应条件下催化剂的性能，表明在高温高空速条件下，３％Ｖ２Ｏ５／Ｃａ３（ＰＯ４）２催化剂的反应活性较好，而３％Ｖ２Ｏ５／Ｚｒ３（ＰＯ４）４催化剂在低温低空速时，反应活性相对较高。在相同的丙烷转化率下，丙烯的选择性从大到小的顺序为３％Ｖ２Ｏ５／Ｃａ３（ＰＯ４）２＞３％Ｖ２Ｏ５／Ｚｒ３（ＰＯ４）４＞３％Ｖ２Ｏ５／ＡｌＰＯ４

用辛烷基硫醇单层保护Au纳米粒子制备CO氧化催化剂Au/γ-Al_2O_3

采用两相法合成出含活性组分Au的辛烷基硫醇单层保护Au纳米粒子(C8AuNPs)的正己烷溶胶,用"逐次浸润"法将C8AuNPs负载在γ-Al2O3上,经真空干燥及活化处理制得Au/γ-Al2O3催化剂.所制得的Au催化剂前体C8AuNPs/γ-Al2O3表面Au粒子平均粒径可控制在2-3nm范围内,且分布比较单一;催化剂活性评价600h后,其表面Au的粒径仍主要分布在2-4nm范围内;真空干燥温度影响Au催化剂的粒子尺寸和催化活性,随着真空干燥温度的提高,Au纳米粒子的粒径增大.将所制备的催化剂用于低温CO氧化反应,催化活性评价结果表明,经25℃真空干燥制得的2.5%(质量分数,w)Au/γ-Al2O3具有较高的活性和长期稳定性,其催化CO完全转化的最低温度为-19℃,在15℃下CO完全转化时Au/γ-Al2O3的单程寿命至少900h;4.0%(w)Au/γ-Al2O3在15℃和进料中含水条件下对CO完全氧化的单程寿命不低于2000h,可见催化剂具有强的抗潮湿中毒特性.综合上述实验结果,讨论了影响Au/γ-Al2O3催化剂活性的可能因素

宫腔镜在体外受精一胚胎移植失败病例中的应用价值

【目的】探讨官腔镜在体外受精-胚胎移植(IVF-ET)失败病例诊断中的应用价值。【方法】收集从1996到2004年在中山大学附属第一和第二医院生殖中心行体外受精-胚胎移植失败患者107例，在我院进行了宫腔镜检查，其中83例进行了内膜活检，总结分析该资料。【结果】官腔镜发现正常官腔74例(69.16％)，异常33例(30.84％)，其中包括宫腔粘连6例、内膜薄6例、宫腔息肉6例、内膜肥厚5例、黏膜下子宫肌瘤4例、宫颈管狭窄3例、内膜炎2例、子宫纵隔1例。83例子宫内膜病理活检则发现正常内膜54例(65.06％)，其中增生期18例、分泌期36例；内膜异常29例(34.94％)，其中黄体功能不全(LDP)12例、轻度增生过长7例(其中有一例同时伴有官腔息肉)，内膜炎症5例、官腔息肉3例、子宫内膜结核2例。【结论】对体外受精-胚胎移植失败病例，进行宫腔镜检查有助于明确病因

High activity Cu Zn Al catalyst For methanol synthesis

用高速碰撞共沉淀法制备的Cu-zn-Al甲醇合成催化剂，其含Cu量与ICI51-2相近，但分散度比ICI51-2高37.3%。在2.067MPA、210℃、3600H-1反应条件下，其甲醇合成活性比ICI51-2高40%，fTIr实验表明，反应中间态是甲酸盐，Cu＋是活性表面物种The Cu Zn Al catalyst For methanol synthesis were prepared by the high speed collision coprecipitation method.Although the Cu contents of both the Cu Zn Al and ICI 51-2 catalysts are similar, the dispersion of the Former is 37.5% higher than that of the latter. Activity of the Cu Zn Al catalyst For methanol synthesis is 40% higher than that of ICI 51-2 when operated at 2.0 MPa, 210℃ and a space velocity 3600 h -1 . FTIR spectra suggests that Formate acid is the intermediate in methanol synthesis and Cu + is the active surFace state.福建省自然科学基金;国家重点实验室资

Carbon nanotubes grow to pillars

In this paper, we report on the self-assembly growth of micro-pillars consisting of well-aligned carbon nanotubes on the uneven surfaces of silicon chips by chemical vapour deposition, which could be useful for the fabrication of electron field emitters, micro-electromechanical devices, interconnection for microelectronics, etc. The mechanism for the growth of isolated pillars within large-area aligned carbon nanotube arrays is also discussed