共查询到18条相似文献,搜索用时 78 毫秒
1.
柴油深度脱芳烃Pd-Pt/USY催化剂的EXAFS研究 总被引:2,自引:0,他引:2
为满足日趋严格的环保要求和适应汽车工业的快速发展,柴油深度脱芳烃已成为国内外普遍关注的课题.近年来的研究表明,Pd-Pt/USY催化剂具有较高的芳烃加氢活性和较强的耐硫中毒能力[’- 相似文献
2.
3.
将水溶性酚醛树脂与金属盐溶液混合形成均相体系,依次通过减压蒸馏、固化、炭化、活化和预硫化处理制备负载金属硫化物的活性炭脱硫剂;研究其对羰基硫(COS)的加氢转化催化活性,考察了担载金属的种类、担载量、反应温度、反应时间和COS入口浓度等因素对催化反应的影响。研究结果表明,水溶性酚醛树脂是制备催化剂炭载体的理想前驱体;Ni Mo双组分催化剂对COS的加氢催化转化活性明显高于Mo单组分催化剂;在金属硫化物/活性炭催化剂上,COS的催化加氢过程属于内扩散控制,加氢反应气氛中一定浓度含硫组分的存在是抑制催化剂失硫及维持其催化活性的必要条件。 相似文献
4.
5.
6.
7.
8.
载体酸性对负载型贵金属催化剂抗硫性能的影响 总被引:3,自引:0,他引:3
贵金属催化剂应用于化学工业过程(例如汽油重整、烯、快烃加氢、尿素合成气净化、汽车尾气净化等)中,由于原料中合硫或反应生成的硫化物(如COS、CS_2、H_2S、SO_2、噻吩等),致使催化剂中毒失活,这引起了人们对催化剂硫 相似文献
9.
10.
采用水蒸气脱铝获得表面酸量不同的USY载体,并用离子交换法制备了金属(Pd Pt)含量为1.15%的双金属催化剂.用NH3的程序升温脱附、X射线衍射、N2吸附-脱附和X射线光电子能谱等方法表征了载体和催化剂.以四氢萘加氢为探针反应,4,6-二甲基二苯并噻吩为硫源,在固定床反应器中考察了催化剂的活性和耐硫性.结果表明硫含量为200μg/g时,载体酸量为626和203μmol/g的两个催化剂的耐硫性最好,而载体酸量更低和更高的催化剂的耐硫性较差,表明载体的酸量太大或太小都不利于催化剂的抗硫性.X射线能量散射分析表明,酸量大时S在酸性位吸附很多,这可能导致催化剂中毒.酸量过小的催化剂抗硫性差则与金属中心缺电子效应较小有关. 相似文献
11.
Advantages and drawbacks of commercial catalysts for gas-phase hydrogenation are considered. The use of modified catalysts, including nickel catalysts modified with heteropoly compounds, is promising. Data on the selective reduction of carbonyl compounds and hydrogenation of aromatic hydrocarbons over these catalysts are presented. Palladium films are shown to be the best catalysts for the selective reduction of acetylene compounds to olefins. 相似文献
12.
The activity and stability of aluminum-palladium catalysts in the hydrogenation of aromatic hydrocarbons mixed with thiophene were studied. The catalysts were obtained by impregnation of γ-A2O3 with aqueous solutions of salts of palladium complexes. Preliminary sulfiding followed by oxidative activation of Pd/Al2O3 catalysts were found to favor the formation of such palladium state on the surface at which the hydrogenation of aromatic hydrocarbons in the presence of sulfur-containing impurities proceeds without a noticeable change in the activity with time. IR spectroscopy showed that the palladium metal surface fragments forming CO complexes with a characteristic absorption band at 1998 cm–1 are resistant to poisoning with sulfur-containing compounds in the hydrogenation of aromatic hydrocarbons. 相似文献
13.
N. A. Zaitseva V. V. Goidin V. V. Molchanov V. V. Chesnokov R. A. Buyanov V. A. Utkin 《Kinetics and Catalysis》2011,52(5):770-773
In order to extend the area of application of the base catalytic system metal-filamentous carbon, the catalytic properties
of Ni-filamentous carbon catalysts have been tested in the hydrogenation of aromatic compounds (benzene, benzyl cyanide, benzophenone,
and nitrobenzene). The selectivity of the catalysts depends on the outer faceting of the active metal particles. The benzene
ring is hydrogenated on the (111) face of the metal nanoparticles, whereas the selective hydrogenation of functional groups
in substituted aromatic compounds occurs on the surface of active component nanoparticles in which the (111) face is blocked. 相似文献
14.
MIL-140-type metal organic frameworks(isoreticular zirconium oxide MOFs) with different aromatic moieties(phenyl,naphthalene,and biphenyl) have been synthesized and employed as the supports of palladium nanoparticles(Pd NPs).The catalysts were characterized by XRD,BET,TEM and CO chemisorption.The results reveal that Pd NPs are homogeneously dispersed on all materials whereas different accessibility to CO is observed.The hydrogenation performance in C=C saturation with respect to the effect of the aromatic moiety is compared.The Pd/MIL-140 A MOF with the highest hydrogenation activity among the three catalysts comprised of different aromatic rings points to a unique Pd-πinteraction between Pd and frameworks consisting of mono-phenyl groups(C_6H_4). 相似文献
15.
Alcohols are produced in high yield by hydrogenation of several aliphatic and aromatic ketones with rhodium complexes as catalysts in the presence of strong alkali. 相似文献
16.
C. Micheaud-Especel D. Bazin M. Guérin P. Marécot J. Barbier 《Reaction Kinetics and Catalysis Letters》2000,69(2):209-216
Bimetallic Pd-Pt catalysts were prepared either by a surface redox reaction (RC catalysts) or by coimpregnation (CI catalysts). RC bimetallic catalysts show a higher sulfur resistance in the course of toluene hydrogenation in the presence of thiophene compared to monometallic palladium and CI bimetallic catalysts. A characterization of the RC catalysts by IR and EXAFS allows to propose a structure of the Pd-Pt crystallites which would explain these results. 相似文献
17.
Zexu Fang Ying Gu Xinran Dong Gen Zhang Lin Li Xiaoguang Zhou Chungui Tian 《中国化学快报》2023,34(9):108128-334
Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination. The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactants are positive to improve the catalytic performance. Herein, we have reported the design of two-dimensional porous Ni-Ni3N-Ni Mo N heterojunction sheets(2D Mo-Ni based nanosheets) for efficient catalytic hydrogenation of the aromatic nitro-compounds. The heterojunction ... 相似文献
18.
Sortais JB Ritleng V Voelklin A Holuigue A Smail H Barloy L Sirlin C Verzijl GK Boogers JA de Vries AH de Vries JG Pfeffer M 《Organic letters》2005,7(7):1247-1250
[reaction: see text] Ruthenacycles obtained by cyclometalation of enantiopure aromatic primary or secondary amines with [(eta6-benzene)RuCl2]2 or with [(eta6-p-cymene)RuCl2]2 are efficient catalysts for asymmetric transfer hydrogenation (TOF up to 190 h(-1) at room temperature). Enantioselectivities in the transfer hydrogenation of acetophenone ranged from 38% to 89%. It is possible to prepare the catalysts in situ, which allows the use of high throughput experimentation. 相似文献