碱性助剂的添加对Ni/CaO-Al2O3催化剂性能的影响

在CH4、 CO2和O2制合成气的反应中, 通过在Ni/CaO-Al2O3催化剂中添加碱性助剂K2O、 MgO和La2O3, 使催化剂的性能得到了改善. 实验结果表明, MgO和La2O3助剂的添加, 有利于提高催化剂的活性;添加K2O, 却相反. 测得催化剂上积炭量的顺序为: Ni-La2O3/CaO-Al2O3相似文献   

碱 性 载 体 对 负 载 型ＣｏＯ 催 化 剂 催 化 性 能 的 影 响

采用XRD、TPR、TPD、XPS和催化活性评价等技术,考察了负载型CoO催化剂的表面性质和其对CH4与CO2重整制合成气反应的催化性能.实验结果表明,碱性载体或助剂MgO和La2O3的添加能有效地改善CoO催化剂的表面结构、抗积炭能力和还原性能,CoO/MgO催化剂显示出最佳的催化反应稳定性,在750℃、GHSV=2500h-1、CH4/CO2原料比为1:1下,连续反应100h内催化剂活性较为稳定,CoO/MgO和CoO/γ-Al2O3催化剂的表面性质本质上是不相同的.     

助剂调变对CoO／γ-Al2O3催化性能的影响

采用XRD、TPR和催化活性评价等技术,考察了负载型CoO催化剂的表面特征和其对CH4与CO2重整制合成气反应的催化性能.实验结果表明,采用浸渍法和焙烧温度为400℃时制备的11.0%CoO/γ-Al2O3催化剂,在反应温度为750 ℃和空速(GHSV)为2 500 h-1下,对CH4和CO2转化反应具有最佳的催化初活性,而大量的Co3O4晶粒的存在能导致催化剂因积炭而快速失去活性.CaO、MgO和La2O3助剂的添加能有效地改善其催化剂的抗积炭能力和还原性能,CoO/(CaO-γ-Al2O3)催化剂显示出最佳的催化反应稳定性,在750 ℃、GHSV=2 500 h-1、CH4/CO2原料比为1:1下,连续反应100 h催化剂活性较为稳定.CoO/(CaO-γ-Al2O3)和CoO/γ-Al2O3催化剂的表面特性本质上是不相同的.     

Mo、W金属氧化物对CH4/CO2重整Ni基催化剂性能的影响

用XRD、XPS、元素分析、TEM和活性评价等方法研究过渡金属氧化物MoO3和WO3对SiO2负载的Ni基催化剂物理化学性质和CH4/CO2重整制合成气催化性能的影响.结果表明,在负载型的镍催化剂中,MoO3和WO3的添加一方面提高了Ni的核外电子密度,减弱了对CH4深度裂解积炭;另一方面使催化剂表面镍的相对浓度降低,结构上起到了隔离、分散金属颗粒的作用,氧的相对浓度升高,有效提高了催化剂的抗烧结和抗积炭能力,显示出较好的催化稳定性.     

焙烧温度对有色金属尾矿载体及Ni基催化剂的性能影响

以尾矿为载体原料,经不同温度焙烧预处理、等体积浸渍制备了一系列负载型Ni/SiO2-CaO-Fe2O3催化剂并用于CO2重整CH4制合成气,重点考察了载体原料的焙烧温度对催化剂性能的影响.用ICP-AES,XRD测定了有色金属尾矿的成分,用H2-TPR,CO2-TPD,TPO等对催化剂的还原性能、吸附性能、抗积炭性能进行了表征.结果表明,载体原料经850℃焙烧后所负载的镍催化剂在800℃条件下CO2转化率为78.5%,CH4转化率为71.2%,CO和H2选择性分别达到92.2%,89.5%.     

助剂对CH4,CO2和O2制合成气反应催化剂性能的影响

考察了NiCaO-Al2O3催化剂中添加碱金属、碱土金属、稀土金属氧化物、CuO助剂及CaO含量对催化剂性能的影响。结果表明,10Ni-2K-2Cu15CaO-Al2O3催化剂对CH4、CO2和O2制合成气反应具有较高的催化活性、选择性和较好的抗积炭性能。通过TPR、CO-TPD、XPS和XRD对催化剂进行表征,发现K2O、CuO和CaO的添加削弱了活性组分Ni与载体Al2O3间的相互作用,增加Ni的电子密度,加速了CO与H2的脱附,从而抑制了CH4深度裂解积炭和CO歧化积炭。此外,这些助剂的添加也提高了Ni的分散度,增强了催化剂的抗积炭能力。     

Utilizing Non-ferrous Metal Tailings to Propare Ni/SiO2 -CaO-Fe2O3 Catalyst for CO2 Reforming of CH4 to Syngas

以尾矿为载体原料,经不同温度焙烧预处理、等体积浸渍制备了一系列负载型Ni/SiO2-CaO-Fe2O3催化剂并用于CO2重整CH4制合成气,重点考察了载体原料的焙烧温度对催化剂性能的影响.用ICP-AES,XRD测定了有色金属尾矿的成分,用H2-TPR,CO2-TPD,TPO等对催化剂的还原性能、吸附性能、抗积炭性能进行了表征.结果表明,载体原料经850℃焙烧后所负载的镍催化剂在800℃条件下CO2转化率为78.5%,CH4转化率为71.2%,CO和H2选择性分别达到92.2%,89.5%.     

三氧化二铝含量对Ni／Zr0.4Ce0.6O2—Al2O3催化剂的CH4—CO2重整反应性能影响

采用水热合成法,制备了不同Al2O3含量的Ni/Zr0.4Ce0.6O2-Al2O3催化剂,采用X－射线衍射（XRD）和扩展X光吸收精细结构（EXAFS）,对催化剂样品进行结构表征;考察了Al2O3的加入对催化剂结构和CH4－CO2重整反应活性的影响。结构表征和活性测试表明,催化剂中存在的主要晶相是Zr0.4Ce0.6O2.Al2O3的加入,使催化剂颗粒度变小,镍的分散度提高,并使反应活性有明显改进;而过量Al2O3的加入,却容易导致积炭。     

抗积炭CH4/CO2重整用Ni/Al2O3催化剂

抗积炭CH4/CO2重整用Ni/Al2O3催化剂     

CH4,CO2和O2制合成气反应中载体对催化剂抗积炭性能的影响

在CH4,CO2 和O2 催化氧化制合成气反应中 ,积炭是催化剂活性减弱的一个重要因素 .通过向Ni/Al2 O3 添加各种氧化物后 ,催化剂的抗积炭性能得到了提高 .实验结果表明 ,催化剂的抗积炭顺序为 :Ni/CaO Al2 O3 >Ni/MgO Al2 O3 >Ni/TiO2 Al2 O3>Ni/CeO2 Al2 O3 >Ni/La2 O3 Al2 O3 >Ni/Y2 O3 Al2 O3 >Ni/Fe2 O3 Al2 O3 >Ni/Al2 O3 ,并通过CO2 TPD ,O2 TPD ,XPS等方法对催化剂进行表征 ,讨论了抗积炭顺序与催化剂性能的关系 .     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。