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Effect of Mn Promoter on Structure and Performance of K-co-Mo Catalyst for Synthesis of Higher Alcohols from co hydrogenation

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Chinese Journal of Chemical Physics 2016年第6期29卷 671-680,I0001页

作者： Wei Xie Li-li Ji Ji-long Zhou Hai-bin Pan Jun-fa Zhu Yi Zhang Song Sun Jun Bao Chen Gao NationalSynchrotronRadiationLaboratory CollaborativeInnovationCenterofChemistryforEnergyMaterialsUniversityofScienceandTechnologyofChinaHefei230029China StateKeyLaboratoryofOrganic-Inorganiccomposites BellingUniversityofChemicalTechnologyBeijing100029China CASKeyLaboratoryofMaterialsforEnergyconversion DepartmentofMaterialsScienceandEngineeringUniversityofScienceandTechnologyofChinaHefei230025China

A series of Mn-doped K-co-Mo catalysts were prepared by a sol-gel method. The catalyst structure was well characterized by X-ray diffraction, N2 physisorption, NH3 temperature- programmed adsorption, in situ diffuse reflectance infrared Fourier transform spectroscopy, and X-ray absorption fine structure spectroscopy. The catalytic performance for higher alcohol synthesis from syngas was measured. It was found that the Mn-doped catalysts ex- hibited a much higher activity as compared to the unpromoted catalyst, and in particular the C2＋ alcohol selectivity increased significantly. The distribution of alcohol products de- viated from the Anderson-Schulz-Flory law. The portion of methanol in total alcohol was suppressed remarkably and the ethanol became the predominant product. Characterization results indicated that the incorporation of Mn enhanced the interaction of co and Mo and thus led to the formation of co-Mo-O species, which was regarded as the active site for the alcohol synthesis. Secondly, the presence of Mn reduced the amount of strong acid sites significantly and meanwhile promoted the formation of weak acid sites, which had a positive effect on the synthesis of alcohol. Furthermore, it was found that the incorporation of Mn can enhance the adsorption of linear- and bridge-type co significantly, which contributed to the formation of alcohol and growth of carbon chain and thus increased the selectivity to C2＋OH.

关键词： co hydrogenation Sol-gel method Mo-based catalyst Mn promoter Higheralcohols synthesis

XPS study of potassium-promoted molybdenum carbides for mixed alcohols synthesis via co hydrogenation

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Journal of Natural Gas Chemistry 2010年第2期19卷 151-155页

作者： Minglin Xiang Debao Li Juan Zou Wenhuai Li Yuhan Sun Xichun She Hunan Changling Petrochemical S＆T Developing co. Ltd. Yueyang 414012 Hunan China State Key Laboratory of coal conversion Shanxi Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 Shanxi China

The X-ray photoelectron spectroscopy （XPS） was used to investigate the surface characteristic of potassium-promoted or un-promoted both β-Mo2C and α-MoC1-x pretreated by syngas at different temperatures,and the promotional effect of potassium on the catalytic performance was also *** results revealed that the content of surface Mo and its valence distribution between β-Mo2C and α-MoC1-x were quite *** by potassium,the remarkable changes were observed for surface composition and valence of Mo distribution over β-*** had strong electronic effect on β-Mo2C,which led to a higher Mo4＋ *** the contrary,potassium had little electronic effect on α-MoC1-x,and K-Mo interaction was ***,Mo0 and Mo2＋ became the dominant species on the catalyst surface,and the Mo4＋ content showed almost no increase as the pretreatment temperature *** terms of catalytic performance of molybdenum carbides,the increase in Mo0 most likely explained the increase in hydrocarbon selectivity,yet Mo4＋ might be responsible for the alcohols synthesis.

关键词： molybdenum carbide potassium-promoted co hydrogenation

Effects of pretreatment and reduction on the co/Al_2O_3 catalyst for co hydrogenation

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Journal of Natural Gas Chemistry 2008年第3期17卷 288-292页

作者： Xiaoping Dai Changchun Yu The Key Laboratory of Catalysis China National Petroleum Corporation China University of Petroleum Beijing 102249 China

The purpose of this study was to investigate the effect of preadsorbed co at different temperatures, calcination temperatures, the combined influence of reduction temperature and time, and pretreatment using hydrogen or syngas as reduction agents on the F-T synthesis （FTS） activity and selectivity of co/Al2O3 catalyst. The reactivity of the carbon species at higher preadsorption temperature with H2 in TPSR decreased, whereas the carbon-containing species showed higher reactivity over co/Al2O3 catalyst with low calcination temperature. This agreed well with the order of catalytic activity for F-T synthesis on this catalyst. The catalytic activity of the catalyst varied with reduction temperature and time remarkably. coDEX optimization gave an optimum reduction temperature of 756 K and reduction time of 6.2 h and estimated C5＋ yield perfectly. The pretreatment of co/Al2O3 catalyst with different reduction agents （hydrogen or syngas） showed important influences on the catalytic performance. A high co conversion and C5＋ yield were obtained on the catalyst reduced by hydrogen, whereas methane selectivity on the catalyst reduced by syngas was much higher than that on the catalyst reduced by hydrogen.

关键词： co hydrogenation co/Al2O3 catalyst co adsorption H2-TPSR surface carbon species reduction condition pretreatment

Catalytic performance of Fe modified K/Mo_2C catalyst for co hydrogenation

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Journal of Natural Gas Chemistry 2011年第5期20卷 520-524页

作者： Minglin Xiang Dudu Wu Juan Zou Debao Li Yuhan Sun Xichun She Hunan Changling Petrochemical S＆T Developing co. Ltd. Yueyang 414012 Hunan China School of Pharmacy Guangdong Medical College Dongguan 523808 Guangdong China State Key Laboratory of coal conversion Shanxi Institute of Coal Chemistry Chinese Academy of Sciences Taiyuan 030001 Shanxi China

Fe modified and un-modified K/Mo2C were prepared and investigated as catalysts for co hydrogenation reaction. compared with K/Mo2C catalyst, the addition of Fe increased the production of alcohols, especially the C2＋OH. Meanwhile, considerable amounts of C5＋ hydrocar- bons and C2= -C4= were formed, whereas methane selectivity greatly decreased. Also, the activity and selectivity of the catalyst were readily affected by the reaction pressure and temperature employed. According to the XPS results, Mo4＋ might be responsible for the production of alcohols, whereas the low valence state of Mo species such as Mo^0 and/or Mo^2＋ might be account for the high activity and selectivity toward hydrocarbons.

关键词： K/Mo2C Fe promoter co hydrogenation

Preparation and characterization of ultrafine Fe-Cu-based catalysts for co hydrogenation

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Journal of Natural Gas Chemistry 2008年第4期17卷 327-331页

作者： Yunlai Su Yingli Wang Zhongmin Liu Department of Chemistry Institute of Industrial Catalysis Zhengzhou University Zhengzhou 450052 Henan China Applied Catalysis Laboratory Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 Liaoning China

The ultrafine particles of a new style Fe-Cu-based catalysts for co hydrogenation were prepared by impregnating the organic sol of Fe（OH）3 and Cu（OH）2 onto the activated Al2O3, in which the organic sol of Fe（OH）3 and Cu（OH）2 were prepared in the microemulsion of dodecylbenzenesulfonic acid sodium（S）/n-butanol（A）/toluene（O）/water with V（A）/V（O） = 0.25 and W（A）/W（S） = 1.50. This catalyst was characterized by particle size analysis, XRD and TG. The results of particle size analysis showed that Fe（OH）3 particles with a mean size of 17.1 nm and Cu（OH）2 particles with an average size of 6.65 um were obtained. TG analysis and XRD patterns suggested that 673 K is the optimal calcination temperature. co hydrogenation produced C＋OH with a high selectivity above 58 wt% by using the ultrafine particles as catalyst, and the total alcohol yield of 0.250 g·ml^-1 ·h^-1 was obtained when the contents of Al2O3 and K were 88.61 wt% and 1.60 wt%, respectively.

关键词： microemulsion conductivity ultrafine Fe-Cu-based catalyst co hydrogenation

Effect of Reduction and Carburization Pretreatment on Iron Catalyst for Synthesis of Light Olefins from co hydrogenation

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Chemical Research in Chinese Universities 2017年第4期33卷 672-677页

作者： AN Tong DANG Dan CHENG Yi Department of Chemical Engineering Tsinghua University Beijing 100084 P. R. China

Effect of reduction and carburization pretreatment on iron catalyst for co hydrogenation to light olefins was investigated. The bulk structure and surface composition of the catalysts during pretreatment were characterized by means of X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS） and high-resolution transmission elec- tron microscopy（HRTEM）. The results indicated that phase transformation of iron phases involved a-Fe203---~Fe304 --,a-Fe both in the bulk and on the surface layers in hydrogen atmosphere. However, a-Fe203 was firstly transformed to Fe3C and then to Fe5C2 in co atmosphere, while in syngas atmosphere directly to Fe5C2. As carburization pretreatment time was prolonged, the degree of carburization on the surface increased, and the increase degree of iron catalyst carburization in co pretreatment was stronger than that in syngas pretreatment. It inferred that surface carbon species was more easily formed in syngas pretreatment instead of iron carbide in co pretreatment. After hydrogen pretreatment, when the catalyst was reduced to a mixture of magnetite and metallic iron, the selectivity to light olefins was relatively low. Under the joint effects of the active sites from surface iron carbide and surface carbon layers blocking the active sites, longer co pretreatment time resulted in higher methane selectivity and less light olefins. The selectivity to methane on H2-pretreated catalyst was lower than that of co-pretreated catalyst.

关键词： Light olefin Fischer-Tropsch synthesis co hydrogenation Iron catalyst Pretreatment

Synthesis of light hydrocarbons from co hydrogenation over co_xMn_(0.06)/SiO_2

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Mining Science and Technology 2010年第2期20卷 296-299,311页

作者： ZHAO, Jianjun ZONG, Zhimin XIE, Hengsen LIU, Tong LI, Jianjun WANG, Taotao WEI, Xianyong school of chemical engineering and technology china university of mining & technologyxuzhou 221008china department of science bengbu collegebengbu 233030china school of chemical engineering and technology china university of mining & technologyxuzhou 221008china school of chemical engineering and technology china university of mining & technologyxuzhou 221008china hubei coal conversion and new carbon material key laboratory wuhan university of science and t

A series of coxMn0.06/SiO2 catalysts were prepared by an impregnation method for catalytic hydrogenation of co to Light Hydrocarbons(LHCs).The catalysts were characterized by XRD,SEM,N2 adsorption and NH3-TPD *** activities were evaluated in a high-pressure micro *** results show that the performance of the catalysts was significantly affected by the amount of co loaded onto the *** activity of the co0.10Mn0.06/SiO2 catalyst was stable with *** co conversion and LHCs selectivity were 95.3% and 98.1%,respectively,for this catalyst at 400 °C.

关键词： co hydrogenation coxMn0.06/SiO2 catalysts light hydrocarbons

Promotion of Mn Doped co/CNTs Catalysts for co hydrogenation to Light Olefins

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Chinese Journal of Chemistry 2013年第6期31卷 826-830页

作者： Liping Tang Chengli Song Xiaolong Yang Mengli Li Bin Hu State Key Laboratory for Oxo Synthsis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou Gansu 730000 China University of Chinese Academy of Sciences Beijing 100049 China

With various contents, Mn was introduced into carbon nanotubes （CNTs） supported cobalt catalysts and the obtained Mn-co/CNTs catalysts were investigated for co hydrogenation to light alkenes and characterized by N2 ad- sorption, X-ray diffraction （XRD）, X-ray photoelectron spectra （XPS）, H2 temperature programmed reduction （TPR）, co temperature programmed desorption （TPD） and transmission electron microscope （TEM）. The results indicate that the addition of a small amount of Mn （0.3 wt%） to CNTs-supported co catalyst significantly increased the selectivity of C2--C4 olefins and decreased the selectivity of CH4. However, with further addition of Mn to the cobalt catalysts, the CH4 selectivity decreased obviously along with the increase of the C5 selectivity. compared with the unpromoted catalysts, the Mn-promoted cobalt catalysts increased the C2=-C4=/C20- C40 molar ratio.

关键词： co hydrogenation cobalt catalyst light alkenes selectivity

Review of Directly Producing Light Olefins via co hydrogenation

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Journal of Natural Gas Chemistry 2003年第1期12卷 10-16页

作者： Chong Wang, Longya Xu, Qingxia WangDalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

Directly making light olefins via co hydrogenation is a promising process toobtain a non-petroleum based supply of alkenes. Limited by the ASF distribution function ofFischer-Tropsch synthesis, the yield of light olefins (C_2-C_4) can not reach the desired levels,which is a great challenge to overcome. Beginning with a brief introduction of F-T synthesis, thispaper provides a review of current research, including thermodynamic analysis, the ASF distributionfunction, the reaction performance of co hydrogenation and slurry reactor studies. The problemscurrently faced by this research area are presented at the end of the article.

关键词： light olefin fischer-tropsch synthesis iron based catalyst promoter co hydrogenation