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1.
采用等体积浸渍和原位合成方法以硝酸铝作为铝源,聚乙二醇1540为模板剂,磷酸氢二铵为辅助剂,硝酸铜为铜源,制备出负载铜金属有序介孔氧化铝催化剂,并采用氮等温吸附—脱附线、透射电镜、X射线衍射、热失重分析多种测试技术对合成催化剂的物理化学性质和结构特征进行了表征。实验结果表明,两种方法均可以制备出比表面积大(大于210m2/g)、孔径分布窄(4nm左右)的负载铜金属介孔氧化铝催化剂。与等体积浸渍法相比,原位合成法所制备的负载Cu金属有序介孔氧化铝金属铜在载体上的分布更均匀,铜离子与载体的相互作用力更强,且孔结构的有序性较好。  相似文献   

2.
在自制的流化床光催化反应装置中进行了TiO2光催化剂的载体选择与催化动力学研究,考察了石英砂、陶瓷球、粗孔硅胶和活性炭颗粒四种栽体的负载型TiO2催化剂光催化降解甲苯的性能及TiO2/粗孔硅胶的催化反应动力学。结果表明,粗孔硅胶是最适用于气固流化床光催化反应体系的载体;TiO2/粗孔硅胶光催化氧化甲苯反应符合Langmuir—Hinshelwood动力学模型,反应速率常数k为2.06262mg/(m^3·min),吸附平衡常数K为0.03683m^3/mg。  相似文献   

3.
通过浸渍法将磷钨酸负载于Worm like状介孔载体上, 制备负载型磷钨酸催化剂,  并采用X射线衍射(XRD)、 红外光谱(FR IR)、 N2吸附 脱附等方法对载体和负载型催化剂进行表征. 将负载型磷钨酸催化剂用于蓖麻油和甲醇的酯交换反应制备生物柴油, 用高碘酸氧化法测定酯交换的转化率. 考察反应温度、 甲醇和蓖麻油物质的量比、 反应时间和磷钨酸负载量等参数对酯交换反应的影响. 结果表明, 在55 ℃, 醇油物质的量比为6, 反应时间2 h, 磷钨酸负载量为50%的催化剂条件下, 酯交换转化率可达95.1%.  相似文献   

4.
利用介孔碳作为载体,制备介孔碳担载Pt-WO3复合催化剂应用于质子交换膜燃料电池(PEMFC)电极.以苯为碳源,采用气相沉积法复制介孔SiO2 Al-SBA-15模板结构合成石墨化介孔碳Cg,采用浸渍法制备无定形介孔碳CMK-3.通过分步沉积,将Pt和WO3担载到介孔碳载体上,采用比表面分析(BET)、X线衍射(XRD)、透射电子显微镜(TEM)、循环伏安法以及单电池极化性能测试对介孔碳担载的复合催化剂进行表征.结果表明:介孔碳作为催化剂载体,其孔道结构有助于催化剂的均匀分散,从而提高催化剂的电催化剂活性.由于石墨化介孔碳的导电性能高于无定形介孔碳,因此Pt-WO3/Cg比Pt-WO3/CMK-3具有更好的电极催化活性.  相似文献   

5.
采用水热法合成碳钛复合材料,以碳钛复合材料为载体制备了钴基费一托合成催化剂.采用氮气物理吸附一脱附、原位x射线衍射(XRD)、透射电子显微镜(TEM)、氢气程序升温还原(H2-TPR)、X射线光电子能谱(XPS)等对催化剂进行了表征,在固定床反应器上对催化剂的费.托合成催化性能进行了评价.结果表明:利用碳改性二氧化钛可明显影响催化剂的催化活性,由于碳的引入导致催化剂更易于还原,催化剂的分散较好,具有更高的费一托合成活性和重质烃选择性(c5+).  相似文献   

6.
对云南曲靖褐煤进行H2O2、HNO3氧解提取黄腐植酸的研究,考察了H2O2、HNO,氧解中N—Mn—TiO2介孔催化剂对黄腐植酸产率和组成结构的影响,对系列氧化产物OFA和NFA进行了官能团含量定性、定量分析,红外光谱分析.研究结果表明:两种N—Mn—TiO2介孔催化剂都能显著提高黄腐植酸的产率,催化剂1(N:Mn:Ti比为16:0.001:1焙烧温度400℃)、催化剂2(N:Mn:Ti比为16:0.001:1焙烧温度100℃)催化H2O2、HNO3氧解时产率较不加时分别增加了32.17%、10.69%和8.61%、7.49%.理化组成研究表明:加入催化剂后,H2O2氧解产物中的总酸性基含量变化不大,羧基含量增加,酚羟基含量降低,HNO3氧解产物中总酸性基、酚羟基含量降低.OFA与NFA的结构组成不同.  相似文献   

7.
通过控制沉淀p H值分别为8、9、10,采用沉淀法合成了3种羟磷灰石(HAP-8、HAP-9、HAP-10)载体,利用浸渍法制备了相应的Pd-Cu/HAP催化剂(PC-8、PC-9、PC-10),并考察了其室温CO氧化催化性能。通过N2-物理吸附、XRD、FT-IR、H2-TPR、CO2-TPD和TEM对载体和催化剂的结构性质进行了表征。结果表明,采用沉淀法制备的载体以及相应催化剂的结构性质受沉淀p H值影响较大。与HAP-8和HAP-10相比,HAP-9载体具有较大的比表面积和孔容、较好的晶体结构以及更多的表面羟基,从而致使PC-9催化剂含有较多与Pd相互作用较强的活性Cu2Cl(OH)3物种和适宜强度的表面碱性位点,因而表现出较高的室温CO氧化催化性能。  相似文献   

8.
利用浸渍法,以K2WO4为活性组分,研究了不同载体制得W基催化剂孔结构、表面化学性质及催化性能。采用BET和化学吸附法等手段对催化剂的孔结构特征和表面化学性质进行了分析表征,催化剂于甲醇-硫化氢体系进行催化性能评价。研究结果表明,不同载体对制得W基催化剂孔结构、表面化学性质及催化性能具有较大的影响;以γ-Al2O3为载体,活性组分K2WO4负载质量分数6%时,制得K2WO4(6%)/γ-Al2O3催化剂表面弱碱量较大、比表面积为215.412 m2·g-1、孔容最大为0.6345 cm3·g-1、CH3SH选择性和收率分别达最大,90.12%和72.65%。  相似文献   

9.
载体特性对催化裂化催化剂性能的影响   总被引:2,自引:0,他引:2  
研究了制备流化催化裂化(FCC)催化剂常用载体的孔结构、酸性特点和反应性能,结果表明胶溶双铝载体和高岭土原位晶化载体具有适合制备重油FCC催化剂的条件.将胶溶双铝载体和高岭土原位晶化载体分别制备成FCC催化剂,采用固定流化床反应器对其反应性能进行了评价,表明采用原位晶化载体制备的FCC催化剂具有更好的重油转化能力.  相似文献   

10.
采用乳液聚合法原位合成以无机物SiO2为核、苯乙烯-丙烯酰胺共聚物(PSAm)为有机/无机壳的核壳粒子,并负载Fe(Ⅱ)后过渡金属催化剂,并考察了PSAm/SiO2核壳载体制备过程中搅拌速率、乳化剂用量等对反应的影响,采用扫描电镜(SEM)、偏关显微镜(PLM)、红外光谱(FTIR)等分析方法对PSAm/SiO2核壳载体进行了表征.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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