Acetylene and Ethylene Hydrogenation on Alumina Supported Pd-Ag Model Catalysts

Adsorption and co-adsorption of ethylene, acetylene and hydrogen on Pd-Ag particles, supported on thin alumina films, have been studied by temperature programmed desorption (TPD). The TPD results show that adding of Ag to Pd suppresses overall hydrogenation activity but increases selectivity towards ethylene, i.e. similar to that observed on real catalysts. The results are rationalized on the basis of a complex interplay between surface and subsurface hydrogen species available in the system, whereby the latter species are the most critical for total hydrogenation of acetylene to ethane.     

乙炔选择加氢催化剂的研究

采用固定床连续流动反应器对12%Ni/CNF、0.5%Pd/CNF、0.5%Pd/α-Al2O33种催化剂上的乙炔加氢反应进行了研究。考察了反应温度、n(H2)/n(C2H2)以及总空速对反应的影响,得到了在n(H2)/n(C2H2)较宽的范围内乙炔加氢为乙烯具有良好选择性的催化剂0.5%Pd/CNF。在50℃,n(H2)/n(C2H2)=23,乙炔空速为106h-1时,乙炔转化率达100%,乙烯收率为64.8%,乙烯选择性为73.8%。     

Effects of Supports and Promoter Ag on Pd Catalysts for Selective Hydrogenation of Acetylene

SiO2, a-Al2O3, g-Al2O3, ZrO2 and CeO2 were used as supports and Ag as promoter to study their effects on Pd catalysts for selective hydrogenation of acetylene. The catalysts were prepared by impregnated synthesis and characterized by XRD, BET and TEM. The catalytic reaction was carried out in a fixed-bed reactor. Overall, the low specific surface area supports were better to increase the ethylene selectivity at high conversion rate of acetylene. Among the four Pd catalysts on low specific surface area supports, the catalyst on low specific surface area SiO2 (LSA-SiO2) retained a high ethylene selectivity even at complete conversion, while the other catalysts showed significant decrease in the selectivity at complete conversion. The performance of Pd/LSA-SiO2 was important to decrease the loss of ethylene in selective hydrogenation of trace acetylene in ethylene. Addition of Ag to Pd/LSA-SiO2 significantly decreased the formation of ethane, C4 alkenes and green oil, and improved the ethylene selectivity to 90% when Pd:Ag=1:1 and 1:3(w). When the ratio of Pd to Ag was above 1, the activity of Pd-Ag bimetallic catalyst was similar to that of Pd monometallic catalyst, and the selectivity of ethylene increased with increasing of amount of Ag. When the ratio of Pd to Ag was below 1, the activity of bimetallic catalyst decreased with increasing of amount of Ag, while the selectivity of ethylene was kept unchanged. The optimum temperature was 200~230℃ for 0.02%(w)Pd-0.02%(w)Ag/LSA-SiO2 to give a high ethylene selectivity and low formation of green oil.     

乙炔前加氢反应器运行稳定性的研究

针对乙烯生产前脱丙烷前加氢工艺技术的特点,分析了影响乙炔前加氢反应器稳定性的因素,提出了工业生产中避免反应器波动的操作方法。     

Structure-Sensitivity of Propylene Hydrogenation over Cluster-Derived Bimetallic Pt-Au Catalysts

A series of Pt and Pt-Au catalysts supported on TiO₂ has been studied using C₃H₆ hydrogenation as a probe reaction to determine the composition of the active catalytic surface. The catalysts were characterized by H₂ chemisorption and TEM analysis to determine concentrations of surface Pt sites for TOF calculations and metal particle size distributions, respectively. Similar TOF values for C₃H₈ formation (approximately 30 sec⁻¹) were observed for a monometallic Pt/TiO₂ and a bimetallic Pt–Au/TiO₂ sample prepared by impregnation from individual salt precursors. In contrast, the TOF for C₃H₈ formation over a Pt₂Au₄/TiO₂ sample prepared from an organometallic Pt₂Au₄ cluster precursor was decreased to 0.07 sec⁻¹, suggesting strong structure sensitivity for the hydrogenation reaction over this catalyst. Characterization results indicate that Pt on the surface of the Pt₂Au₄/TiO₂ catalyst is heavily diluted by Au atoms. In combination with the kinetic results, this suggests that the highly diluted surface ensembles of Pt are too small to effectively catalyze C₃H₆ hydrogenation, although electronic effects induced by the presence of Au adjacent to Pt sites can not be excluded.     

碳二选择加氢催化剂BC-H-20B在乙烯装置上的工业应用

报道了国前碳二选择和氢催化剂BC－H－20B在乙烯装置上的首次开车试用及长周期工业应用情况。试验表明，BC－H－20B碳二加氢催化剂在使用过程中，活性、选择性及稳定性良好，抗波动能力强。通过BC－H－20B催化剂与进口催化剂使用结果比较，证实BC－H－20B催化剂性能优于进口催化剂。该催化剂完全可以在乙烯装置上替代进口催化剂，值得推广使用。     

油脂在镍基催化剂上氢化性能的研究

研究由共沉淀方法制备的镍基催化剂上大豆色拉油加氢活性,测定氢化反应温度180℃,反应压力0．8MPa,反应时间120min,催化剂用量4％g／mL、搅拌转速360r／min条件下氢化油脂的碘值、折光指数、熔点数据,考察改变镍铝比、添加助剂铜铁镧等对催化剂在油脂氢化过程中活性的影响,镍基催化剂有较好的加氢活性。     

NiB非晶态合金催化剂用于可可碱加氢还原反应中的研究

考察了3种催化剂在可可碱合成工序中3-甲基黄嘌呤加氢反应中的活性及效果,用NiB非晶态合金催化剂对加氢还原工艺参数进行了考察实验,确定了最佳工艺条件.结果表明,使用NiB非晶态合金催化剂进行可可碱加氢反应,当氢压0.4 MPa、基温为45℃、反应终温60℃、触媒用量为12∶1、搅拌速度为400 r/min条件下,加氢还原收率较现普遍使用的晶态Raney Ni催化剂有较大提高,可达86.66%.     

芳烃加氢金属催化剂抗硫性研究的进展

介绍了在油品芳烃加氢过程中提高镍金属和贵金属催化剂抗硫性研究的进展，对镍催化剂，添加碱金属、碱土金属和其他组分，调节镍金属的还原度及形成镍硼合金等有一定的效果；对贵金属催化剂，铂和钯形成合金，改变金属的颗粒度和载体的酸碱性能及添加碱金属等常被采用。     

Size-controlled Pd nanoparticles supported on α-Al2O3 as heterogeneous catalyst for selective hydrogenation of acetylene

Size-controlled Pd nanoparticles （PdNPs） were synthesized in aqueous solution, using sodium car-boxymethyl cellulose as the stabilizer. Size-controlled PdNPs were supported onα-Al2O3 by the incipient wetness impregnation method. The PdNPs onα-Al2O3 support were in a narrow particle size distribution in the range of 1-6 nm. A series of PdNPs/α-Al2O3 catalysts were used for the selective hydrogenation of acetylene in ethylene-rich stream. The results show that PdNPs/α-Al2O3 catalyst with 0.03%（by mass） Pd loading is a very effective and sta-ble catalyst. With promoter Ag added, ethylene selectivity is increased from 41.0%to 63.8%at 100 ＆#176;C. Comparing with conventional Pd-Ag/α-Al2O3 catalyst, PdNPs-Ag/α-Al2O3 catalyst has better catalytic performance in acety-lene hydrogenation and shows good prospects for industrial application.     

糠醛加氢制2-甲基呋喃催化剂的研究进展

本文综述了糠醛加氢制2-甲基呋喃所用的3类催化剂铬铜催化剂、无铬铜类催化剂、非晶态合金催化剂的近期研究进展。重点介绍了各类催化剂的制备及其催化性能,并对相关研究进行了评述。同时对糠醛加氢制备2-甲基呋喃催化剂的研究进行了展望。     

预硫化加氢催化剂钝化的研究进展

钝化是预硫化加氢催化剂的一个重要处理步骤,介绍了预硫化催化剂的气体钝化、含氧烃钝化和涂覆剂钝化3种工艺,以及预硫化催化剂钝化的应用和研究进展。经过上述钝化工艺处理后．有效抑制了催化剂的自热或自发燃烧的特性,使预硫化催化剂的运输、存放、保管变得简单安全,这对大规模推广使用器外预硫化催化剂有着重要的意义。     

中低温煤焦油加氢脱氮催化剂研究进展

详细介绍了煤焦油加氢技术,将现有煤焦油加氢转化技术划分为轻组分加氢,脱酚加氢,加氢裂化-加氢改质和全馏分加氢四种,分别介绍了每种技术的工艺流程特点和发展状况。阐述了国内外加氢催化剂研究进展,分析了催化剂中活性金属、载体和助剂的种类及对催化剂性能的影响;结合煤焦油加氢催化特点,展望了加氢脱氮催化剂的研究方向,旨在为煤焦油加氢催化剂研究提供一定的理论依据。     

脂肪酸（或酯）加氢制脂肪醇催化剂进展及评述

论述了脂肪酸（或酯）加氢传统的工业催化剂，以及近年来开发进展的温和条件下的中压催化性能及评述。     

航煤加氢精制装置催化剂匹配装填可行性研究

采用不同的催化剂进行航煤加氢工艺试验,试验结果证明,,采用FH-40A/FH-40B催化剂匹配装填与全部装填FH-40A催化剂进行对比,在满足产品w(S)＜1 μg/g,w(N)＜1 μg/g和溴指数＜150 mg Br/100 g油(即满足分子筛进料要求)的情况下,可以降低加氢精制反应的化学氢耗.     

多相铂催化剂在芳香族化合物加氢中的应用

介绍了负载型铂催化剂、高分子铂络合物催化剂和负载型含铂双金属催化剂等几种多相铂催化剂在芳香族化合物加氢中的应用及各自特点，展示这类催化剂在反应中具有良好的催化活性。     

减少乙烯装置碳二前加氢工艺中CO的影响

分析了碳二前加氢工艺中CO浓度对加氢反应的影响，讨论了CO的生成因素，提出了减少CO生成量及控制CO浓度波动的有效措施：加强注硫操作，降低裂解炉投料温度，防止甲醇进入裂解炉等，以保证装置平稳操作。     

Advanced TEMKIN Reactor: Testing of Industrial Eggshell Catalysts on the Laboratory Scale

In a variety of reactions in the chemical industry, eggshell catalysts with a thin active layer are applied; they are often crushed for laboratory testing. The destruction of the shell can be avoided by a special reactor design. The presented advanced TEMKIN reactor is a further development of the reactor system for testing eggshell catalysts on the laboratory scale published by Temkin and Kul'kova in 1969. It is suitable for kinetic studies and for the detailed investigation of deactivation processes, as shown on the example of selective hydrogenation of acetylene.     

预硫化加氢催化剂钝化机理的研究进展

预硫化催化剂经过钝化处理后,可有效抑制催化剂的自热和硫的脱离,便于催化剂的存储和运输。论述了预硫化加氢催化剂钝化类型和机理的研究,描述了气体钝化过程中,活性点、Mo和载体间相互作用和助剂等因素对钝化后催化剂活性的影响,并初步讨论了液体钝化过程的机理。     

炔烃及二烯烃选择加氢催化剂的研究进展

综述了在炔烃和二烯烃选择加氢制烯烃过程中的催化剂的应用研究进展。