K/MgFeZn-HTLcs催化CO加氢制低碳烯烃性能研究

以MgFeZn-HTLcs为前驱体,制备了不同Mg/Fe/Zn物质的量配比、K改性的K/MgFeZn-HTLcs催化剂,用于CO加氢直接制低碳烯烃反应。采用N2吸附-脱附、SEM、TG、XRD、XPS、H_2-TPR等手段对催化剂进行了表征。结果表明,MgFeZnHTLcs前驱体具有典型的层状结构,孔径分布均一;经焙烧、K改性后仍具有一定的层状结构,但比表面积显著减小,平均孔径增大;新鲜催化剂物相以金属氧化物和铁酸盐为主,反应后K/MgFeZn-HTLcs催化剂主要以Fe_5C_2、MgCO_3和ZnO相存在,K/2Fe-1Zn催化剂主要物相为ZnFe2O_4。在CO加氢反应中,K/MgFeZn-HTLcs催化剂具有较高的C=2-4烯烃选择性和较低的C+5含量,与K/2Fe-1Zn催化剂相比,产物分布明显改善;K/2Mg-2Fe-1Zn催化剂上O/P比值达5.15,C=2-4含量占总烃质量的48.56%。

Highly Efficient Synthesis of Clean Biofuels from Biomass Using FeCuZnAIK Catalyst

Highly efficient synthesis of clean biofuels using the bio-syngas obtained from biomass gasi- fication was performed over Fel.5CulZnlAllK0.117 catalyst. The maximum biofuel yield from the bio-syngas reaches about 1.59 kg biofuels/（kgcat·rh） with a contribution of 0.57 kg alcohols/（kgcat·rh） and 1.02 kg liquid hydrocarbons/（kgcat·rh）. The alcohol products in the resulting biofuels were dominated by the C2＋ alcohols （mainly C2-C6 alcohols） with a content of 73.55%-89.98%. The selectivity .of the liquid hydrocarbons （C5＋） in the hydrocarbon products ranges from 60.37% to 70.94%. The synthesis biofuels also possess a higher heat value of 40.53-41.49 MJ/kg. The effects of the synthesis conditions, including temperature, pressure, and gas hourly space velocity, on the biofuel synthesis were investigated in detail. The catalyst features were characterized by inductively coupled plasma and atomic emission spectroscopy, X-ray diffraction, temperature programmed reduction, and the N2 adsorption-desorption isotherms measurements. The present biofuel synthesis with a higher biofuel yield and a higher selectivity of liquid hydrocarbons and C2＋ alcohols may be a potentially useful route to produce clean biofuels and chemicals from biomass.

Preparation of Highly Active Pt-K/γ-Al_2O_3 Catalyst for o-Phenylphenol Synthesis from o-Cyclohexenyl-cyclohexanone Dehydrogenation

0.5%Pt-K/γ-Al2O3 catalysts for the synthesis of o-phenylphenol（OPP） from o-cyclohexenyl-cyclohexanone （dimer） dehydrogenation were prepared by means of a two subsequent impregnation method. The effects of catalyst preparation parameters, such as K promoters, calcination, and reduction conditions, were investigated. The results showed that the addition of K2SO4 to Pt/γ-Al2O3 catalyst notably promoted the selectivity of OPP, and its optimum content was found to be 6% in mass fraction. The higher activity was obtained when Pt/γ-Al2O3 catalyst was calcined in nitrogen atmosphere at 400--500 ℃ and then reduced at the same temperature for 3 h in hydrogen atmosphere. The conversion of the dimer and the selectivity of OPP were always above 99% and 90%, respectively, over 0.5%Pt-6% K2SO4/γ-Al2O3 catalyst during the pilot scale test of 8000 h.

Improving the denitration performance and K-poisoning resistance of the V_2O_5-WO_3/TiO_2 catalyst by Ce^(4+) and Zr^(4+) co-doping

A series of V2O5‐WO3/TiO2‐ZrO2,V2O5‐WO3/TiO2‐CeO2,and V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalysts were synthesized to improve the selective catalytic reduction(SCR)performance and the K‐poisoning resistance of a V2O5‐WO3/TiO2 catalyst.The physicochemical properties were investigated by using XRD,BET,NH3‐TPD,H2‐TPR,and XPS,and the catalytic performance and K‐poisoning resistance were evaluated via a NH3‐SCR model reaction.Ce^4+and Zr^4+co‐doping were found to enhance the conversion of NOx,and exhibit the best K‐poisoning resistance owing to the largest BET‐specific surface area,pore volume,and total acid site concentration,as well as the minimal effects on the surface acidity and redox ability from K poisoning.The V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst also presents outstanding H2O+SO2 tolerance.Finally,the in situ DRIFTS reveals that the NH3‐SCR reaction over the V2O5‐WO3/TiO2‐CeO2‐ZrO2 catalyst follows an L‐H mechanism,and that K poisoning does not change the reaction mechanism.

Simultaneous catalytic hydrolysis of carbonyl sulfide and carbon disulfide over Al_2O_3-K/CAC catalyst at low temperature

In this work, a series of coal-based active carbon （CAC） catalysts loaded by A1203 were prepared by sol-gel method and used for the simulta- neous catalytic hydrolysis of carbonyl sulfide （COS） and carbon disulfide （CS2） at relatively low temperatures of 30-70 ℃. The influences of calcinations temperatures and operation conditions such as： reaction temperature, 02 concentration, gas hourly space velocity （GHSV） and relative humidity （RH） were also discussed respectively. The results showed that catalysts with 5.0 wt% A1203 calcined at 300 ℃ had supe- rior activity for the simultaneous catalytic hydrolysis of COS and CS2. When the reaction temperature was above 50 ℃, catalytic hydrolysis activity of COS could be enhanced but that of CS2 was inhibited. Too high RH could make the catalytic hydrolysis activities of COS and CS2 decrease. A small amount of 02 introduction could enhance the simultaneous catalytic hydrolysis activities of COS and CS2.

Preparation and Characterization of V-K Catalysts Supported on Porous α-alumina Ceramic Substrate for Diesel Soot Oxidation

The V-K catalysts were produced on porous α-alumina substrate by a solution impregnation route and the compositions and catalytic activities for soot oxidation were studied by XRD, TG/DTG, DSC and TPR. According to the catalytic activity studies, the catalytic activity of the crystalline phases is in the order： KNO3＋KVO3〉K3V5O14＋KVO3. The appearance of excessive KHCO3 phase will lead to the deterioration of catalytic activity when the catalysts contain higher KNO3 content. It is also found that when the K∶V molar ratio is higher than 1∶1, the prepared catalysts show a strong CO2 absorption characteristic and this behavior will become gradually significant with the increasing of K∶V molar ratio. Considerable amount of absorbed CO2 are strongly bonded to the crystal lattice with onset desorption temperature of 200 ℃.

K改性NiMoS/ZnAl氧化物负载型催化剂合成气制低碳醇性能研究

采用共沉淀法和浸渍法,以ZnAl混合金属氧化物为载体,制备了系列不同K/Mo物质的量比的高分散K改性NiMoS/ZnAl催化剂,并对其合成气转化制低碳醇性能进行了研究。结果表明,K的引入可以调变MoS_(2)片层的堆积程度和尺寸,提高NiS_(x)和NiMoS之间的协同作用,促进低碳醇合成(HAS)过程中CHx的插入和非解离CO的插入能力,有效抑制烃类和CO_(2)的生成。其中,K/Mo物质的量比为0.6的KNiMoS/ZnAl催化剂具有最多的双层MoS2结构(33.7%)和适宜的NiS_(x)与NiMoS协同作用,产物中总醇选择性达到69.8%,低碳醇空时产率为78.6 mg/(g·h)。

Study on Co-Effect of K₂SO₄Deposition and Low Concentration SO₂on Performances of V₂O₅/AC Catalysts for Low Temperature SCR

Simulated compounds were prepared by loading K2SO4 onto V2O5/AC catalysts. Study the effect of K2SO4 on V1/AC catalysts in the presence of low concentration SO2. Transient response techniques, TPD was carried out. The results indicated that the DeNO activity of V1/AC catalysts was decreased seriously in the early period of operation, but the deactivation was gradually diminished with SO2 adsorption and then, it was completely eliminated. For the sulphated catalysts (saturated catalysts by sulphate), their SCR activity were free from existence of gaseous SO2. the loss of activity about 10% caused by K2SO4 was found on them. The deactivation of K2SO4 deposited catalysts was due to the decrease of adsorbed and activated NH3, or some acid sites.

STUDY ON APPLICATION OF POTASSIUM TITANATE WHISKER MATERIALS IN PREPARATION OF PHOTOCATALYST

The K2Ti4O9 whiskers were chosen for the catalyst carrier, TiO2/potassium titanate photocatalyst was prepared by Sol-gel method. The product was characterated by X-ray diffraction and SEM. EDS shows that, the main peck included Ti, O, and K in potassium titanate whisker. The main peak of K disappeared and the peaks of Ti, O stayed after whisker was covered. It directed that the surface of sample was covered by TiO2. XRD shows that diffraction peak appeared, which was corresponded to the peak of anatase TiO2. In the reaction device of photochemistry, using middle-pressure mercury lamp as illumination, rhodamine B as simulant pollutant, the photocatalytic performance of TiO2/potassium titanate was studied. Under the same conditions, the lower pH, the larger illuminance, the higher temperature, the greater aeration quantum and the lower initial concentration of rhodamine B, the higher decoloration rate was got. Under our experiment conditions: pH 6, the illuminance of 250W, the temperature of 313K, and the aeration quantum of 2.0L/min. When the concentration of rhodamine B was 8mg/L The photocatalyst of TiO2/potassium titanate was 0.01g/L. The decoloration rate of TiO2/potassium titanate dealt with the rhodamine B reach over 95% in 160min, and compare with TiO2, the decoloration rate of rhodamine B was improved 0.50~1.91 multiple. TiO2/potassium titanate can be used to treatment of dye wastewater.

Research on K-V-rare Earth Metal Catalysts for Diesel Soot Oxidation

Five types of KNO_3-NH_4VO_3-rare earth metal nitrate（K-V-rare earth metal） catalysts supported on a-porous alumina ceramic substrates were prepared by a coating method. All the catalysts were characterized by X-ray diffraction and thermogravimetry/differential scanning calorimetry. Catalytic activities were evaluated by a soot oxidation reaction using a temperature-programmed reaction system. The experimental results show that the addition of rare earth metal compound could obviously improve the catalytic activities of the K-V-based catalysts. The proper ratio of K-V-rare earth metal catalysts can not only lower the soot onset ignition temperature, but also quicken the soot oxidation rate. The crystalline phases formed by K, V, and rare earth metal are stable.

K-CoMoS催化剂上合成气制低碳醇的宏观动力学

针对K促进的掺杂Co的MoS_(2)催化剂(K-CoMoS),设计合成气(H_(2)+CO)制低碳醇的动力学实验,利用固定床反应器测定反应数据,建立CO消耗和低碳醇生成的宏观动力学模型。模型参数回归结果表明,CO消耗活化能为105.16 kJ·mol^(-1),低碳醇链增长活化能为56.9 kJ·mol^(-1),链终止活化能为55.2 kJ·mol^(-1),链增长的反应速率低于链终止的反应速率,是速率控制的关键步骤。通过动力学模型预测,提高CO分压有利于提高低碳醇的选择性,与实验值一致,证明了该动力学模型的合理性。

不同K源对NaY分子筛合成的影响

通过向水玻璃中添加不同的钾源(KCl和KOH),考察其对NaY分子筛合成的影响,并采用XRD、N 2物理吸附-脱附及SEM对样品进行表征。结果表明,当水玻璃中的K+浓度为0.1 mol·L^(-1)时,无论何种K源都不会对NaY分子筛的合成造成影响。而K+浓度增加到0.2 mol·L^(-1)时,添加KCl的合成体系中有极少量的杂晶生成,相对结晶度降至74%,进一步增加K+浓度到0.3 mol·L^(-1)、0.4 mol·L^(-1)时,样品中出现了大量的无定型物质。而在添加KOH的体系中,相同K添加量下,KOH对NaY分子筛的影响要远小于KCl。随着添加量的增加,相对结晶度和比表面积也呈下降趋势。SEM表征结果表明,KOH添加量增加到0.3 mol·L^(-1)、0.4 mol·L^(-1)时,合成样品中没有无定形物质形成,但出现了大量菱沸石,说明KOH导向生成菱沸石。

Au-K/C催化剂用于乙炔氢氯化反应制氯乙烯的催化性能

采用过量溶液浸渍法制备了用于乙炔氢氯化反应的Au-K/C催化剂,并对其进行了X射线衍射(XRD)、扫描电子显微镜(SEM)和BET表征。分析结果表明,Au-K/C催化剂活性组分在载体表面高度分散。在常压固定床反应器中,通过考察温度、空速和反应物配比对Au-K/C催化剂活性的影响,得到了基于Au-K/C催化剂的乙炔氢氯化反应的优化条件,即:反应温度170℃,乙炔空速120 h-1,原料配比VHCl/VC2H2=1.10。在该条件下,对Au-K/C催化剂连续进行120 h的活性考察,结果显示催化剂活性无明显降低,乙炔转化率大于96.0%,氯乙烯选择性不低于99.5%。

K/γ-Al_2O_3催化丙酸甲酯合成甲基丙烯酸甲酯

以K/γ-Al2O3作催化剂,丙酸甲酯(MP)为原料高效合成了甲基丙烯酸甲酯(MMA),考察了反应温度、MP质量分数、甲醛来源、K负载量、原料摩尔比及催化剂煅烧温度对反应的影响。结果表明,反应的最佳工艺条件为:反应温度320℃,MP质量分数20%,三聚甲醛作甲醛来源,催化剂K负载量为12.5%,MP与甲醛的摩尔比为1∶1,催化剂煅烧温度为1100℃。在此条件下,MMA收率为39.2%,选择性为76.1%。进一步研究表明,随着焙烧温度的升高,Al2O3的晶型也发生转变,γ-Al2O3比α-Al2O3的活性高,K—O—Al键的生成有利于催化剂性能的提高。

助剂Cu、K对F-T合成铁基催化剂作用的表征研究

采用连续共沉淀和喷雾干燥技术相结合的方法制备了一组Cu、K助剂单独或同时加入的微球状Fischer-Tropsch(F-T)合成铁基催化剂,借助低温N2 吸附、MES、XRD、H2 -TPR、CO-TPR研究了Cu和K助剂对催化剂织构、还原性能以及还原和炭化过程中的物相变化的影响。结果表明,K助剂的加入能明显提高催化剂的比表面积和铁物相在催化剂中的分散程度,增加了Fe2O3 与SiO2 间的相互作用;当催化剂在H2 和合成气中还原时,Cu助剂的加入有利于催化剂的还原和Fe3O4 的生成,在CO中还原时,Cu助剂的加入则有利于α-Fe的生成和稳定化。在H2 和合成气中,单独K助剂的加入会抑制催化剂的还原或炭化,而Cu和K助剂的同时加入在H2、CO和合成气下均可使催化剂的还原或炭化能力明显提高,表明Cu和K助剂间存在一定的协同作用。

合成低碳醇超细Mo-Co-K催化剂的TPD研究

A series of ultrafine Mo Co K catalysts with different Co/Mo ratios but constant potassium content were characterized by TPD technique and their catalytic performance for higher alcohol synthesis was investigated The results indicated that there are two kinds of adsorption sites, ie, low temperature adsorption sites (LTAS) around 90?℃ and high temperature adsorption sites (HTAS) above 400?℃ for H 2 and CO on the surface of the catalysts The desorption temperature of HTAS for H 2 and CO as well as the desorption amount of HTAS for H 2 were strongly influenced by the Co/Mo ratio of the catalysts It was found that the addition of Co into the ultrafine Mo K catalyst resulted in a decrease of the HTAS desorption temperature and an increase of the HTAS desorption amount for H 2 As the Co/Mo ratio increased further, the HTAS desorption amount for H 2 increased accordingly while the HTAS desorption temperature remained constant However, the HTAS desorption temperature for CO was found to be mainly influenced by the Co/Mo ratio, and the HTAS desorption temperature got its minimum at the Co/Mo ratio of 1∶7 It was found that a weaker adsorption of H 2 and CO on the HTAS and an appropriate H 2 adsorption amount were favourable for the formation of higher

异丁烷在Pt-Sn-K/Al_2O_3上的脱氢反应

The TPR experiments and DTA TG results showed that catalyst Pt Sn K/Al 2O 3 had a better selectivity(94 60%) and yield(48 71%) for isobutane dehydrogenation than Pt Sn/Al 2O 3.

用于浆态床FT合成的Fe-Cu-K-Si催化剂的初步考察

使用连续共沉淀反应器制备了浆态床FT合成用的Fe Cu K Si催化剂。考察了钾含量、粘合剂的添加以及催化剂还原方法等对催化剂性能的影响。 1L高压搅拌釜的试验结果表明粘合剂添加方法B和低压CO还原条件下的No 9催化剂性能较好。在质量空速为无载体Fe Cu K催化剂 1 5倍的条件下 ,No 9催化剂的合成气转化率 ,C+1 和C+5产物的产率均高于无载体Fe Cu K催化剂 ,甲烷选择性为 3 2 %。特别在富CO合成气条件下C+5的单程产率达到 1 30g m3 (CO +H2 )以上。假设对氢为一级反应动力学的条件下 ,使用表观速率常数对No 9催化剂的反应活性的经时变化作了考察 。

Co-K-Mo/γ-Al_2O_3催化剂的合成低碳醇性能及其结构研究

氧化态K-K－MoO3／γ－Al2O3催化剂中添加Co（NO3）2后在空气中四个不同温度下焙烧再硫化，制得Co-KK－MoO3／γ－Al2O3催化剂，对其CO加氢合成低碳醇的催化反应性能进行了评价，运用XRD，LRS及EXAFS等手段对催化剂及其氧化态前躯体的结构进行了表征．活性测试结果表明加Co后于500－650℃焙烧制得的催化剂活性较高，且使C2＋醇比例增加．结构分析结果显示加Co后350℃焙烧时，Co主要以氧化物的形式覆盖在催化剂的表面，与钾钼物种作用较弱，硫化后Co以八面体配位的硫化物形式存在，焙烧温度升高后，Co组分与钾钼组分的作用增强，硫化后Co主要以四面体配位的硫化物形式存在；当焙烧温度达800℃时，生成了较多的难以被硫化还原的铝酸钴物种．催化剂的合成醇活性与Co的存在形式明显有关．

K对Pt／γ-Al2O3催化剂制备邻苯基苯酚催化性能的影响

通过加入不同K助剂对0.5%Pt/γ-Al2O3催化剂进行改性,考察了其在由环己烯基环己酮脱氢制邻苯基苯酚(OPP)的催化反应中的催化性能,利用XRD、H2-TPD、NH3-TPD、CO2-TPD等手段对催化剂进行表征,并与反应结果关联。研究表明,Pt/γ-Al2O3催化剂加入K助剂后不同程度地减少了催化剂表面的酸、碱量和对氢的吸附量;采用6.00%K2SO4作为助剂,明显地弱化了催化剂表面的强酸和强碱中心,减少了酸、碱量,调整了催化剂表面对中间产物、OPP和氢吸附量,抑制了副反应,可显著提高生成OPP的选择性,在LHSV0.12h-1、H2空速33ml.g-1.h-1、380℃的反应条件下,环己烯基环己酮转化率为100%,OPP选择性达90%以上。