In Situ Raman Technique On Catalysis Studies

研制了分别适用于MACrO-rAMAn及MICrO-rAMAn谱仪的高性能原位样品池。性能指标温度：从173k-1073k连续可调，精度±0.5-2k；压力：常压至10MPA.真空度：10-6TOr：相态：气固相及液相。指标表明，多数类型的化学反应都可以在上述样品池内再现。此外，还提出了建立光谱——色谱——质谱——微型反应器联用装置的技术方案，用于考察反应过程催化剂表面结构，吸附物种与产物三者之间的内在联系，以期将催化反应机理的研究提高到原位动态分子水平。Two high perFormance in situ Raman cells Fit in with Macro Raman and Micro Raman spectrograph respectively have been designed and Fabricated. SpeciFications Temperature: 173K 1073K continuously adjustable, accuracy ±0.5 2K, Pressure: atmosphere to 10 MPa, Vacuum:10 6 torr, Phases: gas solid and liquid.The speciFications indicate that most chemical reactions can take place in the cells.A plan to combine in situ Raman technique with GC MS and Microreactor has been proposed, which is very useFul to study the relationship among catalyst surFace structure, adsorbed species and products under reacting conditions.The plan is expected to characterize the mechanism of the catalysis reaction at dynamic molecular level in situ.厦门大学固体表面物理化学国家重点实验室资

激光喇曼光谱仪的聚光会集系统

厦门大学固体表面物理化学国家重点实验室资

New Collection Lens System of Raman Spectrometer For Electrochemical Time-resolved Raman Measurements

为了进一步提高拉曼谱仪检测灵敏度，对S3000型拉曼光谱仪的聚光会集系统进行了重新设计，新设计的聚光会集系统可以显著提高拉曼散射光的光强，理论上收集光强增大9倍。采用配制该聚光会聚系统和以光学多道分析仪（OMA）作为信号检测器的拉曼谱仪，并采用分区间录谱方法进行了电化学现场时间分辨测量，获得了质量较高的时间分辨值为5MS的SErS谱图，该时间分辨值目前尚未见报道。以Ag/SCn-为体系初步结果表明：提高检测灵敏度将有助于从分子水平研究电化学界面动态过程.in order to improve detection sensitivity, the collection lens system of the 53000 Raman spectrometer has been redesigned.With a special homemade collection lens system, the intensity of Raman scattering light can be improved considerably, up to a Factor of nine theoretically.By selecting the "Fastmode" of "single Region" sub-menu From the "Scan Mode"menu in the opticalmulitichannel analyzer (OMA), the time resolved SERS spectrum with 5mstime resolution has been obtained.This Fast time resolution has not been previously reported.It is shown that the improving of the detection sensitivity will be helpFul to the studies on dynamic process of electrochemical interFace at molecular level.国家自然科学基金;厦门大学固体表面物理化学国家重点实验室资

多壁碳纳米管及其对H_2吸附体系的Raman光谱

利用原位和非原位紫外 Raman谱法 ,对以 CH4 为碳源 ,由催化法制备的多壁碳纳米管( MWCNTs) ,K+-修饰的该类 MWCNTs,以及它们对 H2 的吸附体系进行了 Raman谱表征 ,观测到可分别归属于类石墨结构的基频模 D和 G以及它们的三阶组合频 ,表面 C-H3基和 C-H2 基等的特征Raman峰 ;H2 在这类碳纳米管上的吸附态包括解离吸附生成表面 C-H3和非解离吸附分子氢 H2 ( a) ;在相同实验条件下 ,K+-修饰体系上这两类氢吸附物种的表面浓度都比未经 K+-修饰的相应体系高

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

STUDY ON THE THERMAL DEGRADATING PRODUCTS OF NATURAL RUBBER/CLAY COMPOSITE BY MEANS OF IN-SITU INFRARED SPECTROMETRY

将粘土经还原剂及酸处理 ,再与天然胶乳共沉制备粘土胶复合材料 ,用带原位样品池的傅立叶变换红外光谱仪动态研究粘土胶复合材料在不同温度下热降解气相产物。在低分解温度下 ,粘土胶分解产物主要是乙烯、低分子烯烃类及含羰基化合物 ;随分解温度升高 ,则低分子烯烃含量减少 ,较长链烯类生成 ,并同时产生大量烷烃类分解产物。随着粘土中 Cu,Mn,Co,Fe等金属组分含量升高 ,粘土胶分解产物中含羰基氧化产物、烯烃及 CO2 含量增加 ,说明金属组分对粘土胶降解氧化产生促进作用After treating by reductant and inorganic acid, the clays were coagulated with natural latex to prepare natural rubber clay composites. The composites were studied in different decomposition temperatures by using in situ FTIR. In lower decomposition temperature, the decomposing gaseous products of the composites mainly were ethylene, lower molecular weight olefin and carbonyl compounds. With the increase of degradation temperature, the contents of lower molecular weight olefin reduce and more higher molecular weight olefin and alkyl compounds form. Furthermore, with the increase of the contents of the metal component in the clay, such as Co, Mn, Cu and Fe, the decomposing gaseous products contain more olefin and carbonyl compounds as well as CO 2. The metal components in the clay accelerate the oxidative degradation of natural rubber/clay composites.国家自然科学基金项目 (5 9760 0 1) ;; 海南省自然科学基金资助项目 (5 960 1

乙烷氧化脱氢制乙烯纳米Sm_2O_3催化剂的研究

采用XRD,TEM,BET,CO2 TPD,O2 TPD和催化剂性能评价等方法对溶胶 凝胶法制备的纳米Sm2O3的物相、颗粒度、比表面、碱性、吸附活化氧物种的能力和催化剂的ODE性能进行了表征和评价,并与常规Sm2O3进行了比较.实验结果表明,纳米Sm2O3催化剂具有较佳的低温ODE反应性能,在500～600℃的温度范围内,纳米Sm2O3的乙烷转化率和乙烯选择性均优于常规Sm2O3,其原因主要与纳米催化剂体系具有较大比表面,较多的表面缺陷位,较弱的碱性和不同于常规催化剂体系的物相结构并因此更有利于吸附和活化氧物种等因素有关.采用高温原位显微Raman光谱对纳米Sm2O3上ODE反应活性氧物种的表征结果表明,O22-是Sm2O3催化剂上ODE反应的活性氧物种

负载型Rh,Ru催化剂上甲烷部分氧化制合成气反应机理的原位时间分辨红外光谱研究

采用原位时间分辨红外光谱(in situ TR-FTIR)技术, 在500~600℃、时间分辨率优于0.3 s的条件下, 对CH4/O2/He (2/1/45, 摩尔比)混合气在不同预处理后的Rh/SiO2, Ru/?-Al2O3和Ru/SiO2上的反应及其与催化剂上吸附CO物种的作用情况进行了跟踪、考察. 实验结果表明, 在还原态和工作态Rh/SiO2上, CO是POM反应的初级产物. 由甲烷直接脱氢生成表面吸附氢和CHx (x = 1~3)物种, 后者再进一步氧化生成CO是Rh/SiO2上POM反应的主要途径. 在Ru/?-Al2O3, Ru/SiO2和氧化态的Rh/SiO2上, CO2是CH4/O2/He混合气反应的初级产物. CH4与CO2和H2O的重整反应是Ru/?-Al2O3和Ru/SiO2上CO和H2生成的主要途径. 在Rh/SiO2和Ru/?-Al2O3上, 催化剂表面吸附CO物种的进一步氧化是POM反应中CO2生成的重要途径之一.国家重点基础研究发展规划项目!(批准号: G1999022408);高等学校博士学科点专项科研基

In-situ Raman Spectroscopic Study of La 2O 3-BaO Catalysts

对于lA0.2bA0.8-XCAX（O，CO3）其中X＝0.0、0.2、0.4、0.6氧化物在973k及甲烷氧化偶联（OCM）条件下，无CA2＋的样品可用表面bACO3和（lAO）2CO3的rAMAn谱及810CM-1附近的O2-2特征峰来表征；含CA2＋的样品，则表现了混合碳酸盐（CA，bA）CO3的特征，还有位于1135CM-1（W）和810CM-1（W）的O-2、O2-2瞬时态氧物种；973~1053k发现OCM反应活性随温度和CA2＋含量而增加，C2烃选择性也随OCM反应温度增大；1053k时，CA2＋含量的增加，C2烃选择性略有下降，这些结果指出O-2是OCM反应的活性氧物种，它在较高温度下与CH4作用，且具有较好的C2烃选择性和较大的反应活化能。For a series of La-Ba-Ca-(O,CO 3) catalysts under methane-oxidative-coupling conditions at 973K,the Ca-Free sample was characterized by Raman bands due to surFace carbonates of BaCO 3 and (LaO) 2(O,CO 3) phases,and a weak and broad band around 810cm -1 ,probably due to O 2- 2;the Ca-containing samples showed Raman bands of surFace carbonates associated with (Ba,Ca)CO 3 phase and minor amount of BaCO 3 phase (but not with lanthania phase),and active-oxygen bands at 1135cm -1 (w) and 810cm -1 (w,br) attributed to O - 2 and O 2- 2 transient species,respectively.At 973～1053K,the activities of all the samples were Found to increase with increasing OCM temperature and with increasing calcium contents.The C 2-selectivities increased with increasing temperature For all the samples,and increased with increasing calcium contents at 973K,but decreased slightly with increasing calcium contents at 1053K.These results strongly indicate that O - 2 might be an active oxgen-species reacting with CH 4 with higher C 2-selectivity and higher activation energy,becoming suFFiciently active only at higher temperature.国家自然科学基

Studies on Catalytic Dehydrogenation of Methanol to Formaldehyde

EFFects of various Factors on the reaction conversion were calculated by theapplication of selF-progranund software and thermodyntalc data; Activities and selectiv-ities of various ZnO/silica-based catalysts were compared; Reaction mechhasm based onthermodyntalc equilibrium and products distribution of the reactions was also discussed厦门大学固体表面物理化学国家重点实验室资