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Insights into the size effect of ZnCr_(2)O_(4)spinel oxide in composite catalysts for conversion of syngas to aromatics

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Green Energy & Environment 2023年第2期8卷 530-537页

作者： Yi Fu Youming Ni Wenhao Cui Xudong Fang Zhiyang Chen Zhaopeng Liu Wenliang Zhu Zhongmin Liu National Engineering Laboratory for Methanol to Olefins Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023LiaoningChina University of Chinese Academy of Sciences Beijing100049China

Direct conversion of syngas to aromatics(STA)over oxide-zeolite composite catalysts is promising as an alternative method for aromatics production.However,the structural effect of the oxide component in composite catalysts is still ambiguous.Herein,we investigate the size effect by selecting ZnCr_(2)O_(4)spinel,as a probe oxide,mixing with H-ZSM-5 zeolite as a composite catalyst for STA reaction.The CO conversion,aromatics selectivity and space-time yield(STY)of aromatics are all significantly improved with the crystal size of ZnCr_(2)O_(4)oxide decreases,which can mainly attribute to the higher oxygen vacancy concentration and thus the rapid generation of more C1oxygenated intermediate species.Based on the understanding of the size-performance relationship,ZnCr_(2)O_(4)-400 with a smaller size mixing with H-ZSM-5 can achieve32.6%CO conversion with 76%aromatics selectivity.The STY of aromatics reaches as high as 4.79 mmol g_(cat)^(-1)h^(-1),which outperforms the previously reported some typical catalysts.This study elucidates the importance of regulating the size of oxide to design more efficient oxidezeolite composite catalysts for conversion of syngas to value-added chemicals.

关键词： Size effect Syngas conversion Aromatics ZnCr_(2)O_(4)oxide H-ZSM-5 zeolite

Modulated hydrocarbon distribution of gasoline deriving from butene conversion in the presence of syngas

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Journal of Energy Chemistry 2022年第10期31卷 416-421,I0010页

作者： Yi Ding Feng Jiao Xiulian Pan Xinhe Bao Department of Chemical Physics University of Science and Technology of ChinaHefei 230026AnhuiChina State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy2011-Collaborative Innovation Center of Chemistry for Energy MaterialsDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

With the expansion of butene production capacity,clean and efficient conversion of mixed butene attracts increasing attention.Herein we report direct co-conversion of butene and syngas to highquality gasoline enabled by a bifunctional OXZEO catalyst comprising ZnCrO_(x) oxide and ZSM-5 zeolite.A gasoline selectivity of 71.6% at 98.1% butene conversion and 26.2% CO conversion have been obtained under the reaction conditions of 360℃,3 MPa and 3000 mL g^(-1) h^(-1).The space time yield of gasoline of0.25 g·g^(-1) h^(-1) is achieved.Interestingly,the presence of syngas can effectively facilitate iso-paraffin production while hindering the formation of aromatics.This is attributed to the prohibited hydrogen transfer aromatization process of butene on ZSM-5 in the presence of H2.Fu rthermore,the formation of isomers of gasoline range hydrocarbons is favored because the active intermediates generated from CO/H_(2) activation over ZnCrO_(x) oxide could react with butene over ZSM-5 zeolite.Thus,the product distribution among gasoline range hydrocarbons is modulated with reduced heavy aromatics and improved iso-paraffins,which is desirable for application as fuels.This provides an alternative environmentally friendly technology to utilize still increasing mixed butene.

关键词： Butene utilization Bifunctional catalysts OXZEO Syngas conversion Gasoline

The newly-assisted catalytic mechanism of surface hydroxyl species performed as the promoter in syngas-to-C2 species on the Cu-based bimetallic catalysts

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Green Energy & Environment 2023年第2期8卷 487-498页

作者： Chenyang Li Yuan Zhang Debao Li Baojun Wang Christopher K.Russell Maohong Fan Riguang Zhang State Key Laboratory of Clean and Efficient Coal Utilization Taiyuan University of TechnologyTaiyuanShanxi030024China Key Laboratory of Coal Science and Technology(Taiyuan University of Technology) Ministry of EducationChina State Key Laboratory of Coal conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuanShanxi030001China College of Engineering and Applied Science University of WyomingLaramieWY82071USA Davidson School of Chemical Engineering Purdue UniversityWest LafayetteIN47906USA School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA30332USA School of Energy Resources University of WyomingLaramieWY82071USA

In the conversion process of syngas-to-C_(2)species,the OH species are inevitably produced accompanying the production of key intermediates CH_(x)(x=1-3),traditionally,the function of surface OH species is generally accepted as the hydrogenating reactive species.This work for the first time proposed and confirmed the assisted catalytic mechanism of surface OH species that performed as the promoter for syngas-to-C_(2)species on Cu-based catalysts.DFT and microkinetic modeling results reveal that the produced OH species accompanying the intermediates CH_(x)production on the MCu(M=Co,Fe,Rh)catalysts can stably exist to form OH/MCu catalysts,on which the presence of surface OH species as the promoter not only presented better activity and selectivity toward CH_(x)(x=1-3)compared to MCu catalysts,but also significantly suppressed CH_(3)OH production,providing enough CH_(x)sources to favor the production of C_(2)hydrocarbons and oxygenates.Correspondingly,the electronic properties analysis revealed the essential relationship between the electronic feature of OH/MCu catalysts and catalytic performance,attributing to the unique electronic micro-environment of the catalysts under the interaction of surface OH species.This new mechanism is called as OH-assisted catalytic mechanism,which may be applied in the reaction systems related to the generation of OH species.

关键词： Syngas conversion C_(2)species Cu-based catalyst Surface OH species Assisted catalytic mechanism

Titanium-Promoted Rh-Mn-Li/SiO_(2) for C_(2)-Oxygenates Synthesis from syngas: Effect of Low Titanium Loading

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Journal of Natural Gas Chemistry 2005年第4期14卷 199-206页

作者： Weimiao Chen Yunjie Ding Dahao Jiang Zhendong Pan Hongyuan Luo Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China

Addition of small amounts of Ti oxide to Rh-Mn-Li/SiO2 catalysts unexpectedly results in an increase in their activity for C2-oxygenates production from syngas. Continuously increasing Ti loading depresses catalyst activity. The effect of Ti at low level on the catalytic properties in the CO/H2 reaction has been studied by various techniques. The characterization results indicate that the existence of Ti species has no effect on the ability of Rh to dissociate CO molecules and on the Rh dispersion. On the other hand, it is shown that trace amount of Ti strengthens the adsorption of CO and increases the amount of strongly adsorbed CO that can be hydrogenated and therefore improves the activity. The RhMn interaction intensity, which can be regulated by Ti doping, seems to be the main reason to achieve higher yield of the desired reaction products.

关键词： rhodium titanium CO hydrogenation C2-oxygenates Syngas conversion

Synthesis of Molybdenum Phosphide Catalyst By RF Induction Thermal Plasma

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Synthesis of Molybdenum Phosphide Catalyst By RF Induction T...

EFFECT OF MOLYBDENUM PROMOTER ON THE Cu-Co BASED CATALYSTS

中国化学会第九届全国无机化学学术会议

作者： Xuemin Liu Jianli Li Xiaojun Gu Haiquan Su School of Chemistry and Chemical Engineering Inner Mongolia University

Mo-based catalysts are considered to be the most promising catalysts for Syngas conversion due to their unique nature of sulfur tolerance and anti-coking. Several Mo compounds have been investigated for synthesis gas conversion. Mo P catalyst has been reported to have unusual catalytic activities and different product distributions on Syngas conversion. Herein, a new method, RF induction thermal plasma, had been employed to prepare Mo P catalyst. The effect of feed rate and carrier gas rate on product purity was studied by XRD, SEM and TEM. Thanks to some special properties of the plasma（high temperature, concentration of energy, high number of charged particles etc.） and a short resident time in the reaction region, they are characterized in most cases by small particle size and high crystal lattice defect and hence with high activity. Therefore, Mo P catalyst prepared by RF induction thermal plasma will be used on Syngas conversion.

关键词： MoP catalyst RF induction thermal plasma Syngas conversion

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Journal of Energy Chemistry 1995年第1期 1-11页

作者： KIEFFER R. KIENNEMANN A. Laboratuire de Chimie Organique Appliquee EHICS rue Blaise Pascal 67008 Strasbourg France

The synthesis of mixed alcohols (C1-C5) from syngas has been studied at 6. 0 MPa over modified Co/CuLaZr catalysts. The molybdenum addition enhanced greatly the activity and the selectivity to alcohols. The improvement of hydrogenation capacity of the system via a reversible spillover effect of hydrogen could explain this effect, together with a great capacity of CO insertion, illustrated by the effect of C2H4 addition as a probe to syngas. Under our experimental conditions, a mixed alcohol production of 147.1g/kg. cat/h containing a proportion of 33. 1% of higher alcohols (C2+OH) was obtained with a selectivity to ROH of 52. 8%.

关键词： Syngas conversion alcohol synthesis copper-cobalt catalysts molybdenum promoter probe molecule tests