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Journal of Natural Gas Chemistry 2012年第2期21卷 178-183页

作者： Atiyeh Ranjbar mehran rezaei Catalyst and Advanced Materials Research Laboratory Chemical Engineering DepartmentFaculty of Engineering University of Kashan Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan

Nanocrystalline calcium aluminates with different CaO/Al2O3 ratios were prepared by a facile co-precipitation method using Poly（ethylene glycol）-block-poly（propylene glycol）-block-poly（ethylene glycol）（PEG-PPG-PEG, MW： 5800） as a surfactant. They were employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by X-ray diffraction （XRD）, N2 adsorption （BET）, temperature-programmed reduction and oxidation （TPR-TPO）, and scanning electron microscopy （SEM） techniques. Catalysts showed a relatively high catalytic activity and stability. TPR analysis revealed that the catalysts with higher CaO content are more difficult to be reduced. TPO analysis showed that the 5 wt%Ni/CA and 5 wt%Ni/C12A7 catalysts with higher CaO amount were effective against coke deposition.

关键词： calcium aluminate nickel catalyst dry reforming

Effect of Ni loadings on the activity and coke formation of MgO-modified Ni/Al_2O_3 nanocatalyst in dry reforming of methane

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Journal of Energy Chemistry 2014年第5期23卷 633-638页

作者： Zahra Alipour mehran rezaei Fereshteh Meshkani Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan

MgO-modified Ni/Al2O3 catalysts with different Ni loadings were prepared and employed in dry reforming of methane （DRM）. The effect of Ni loadings on the activity and coke formation of Ni/MgO-A1203 catalysts were investigated. The synthesized catalysts were characterized by XRD, N2 adsorption-desorption, SEM, TPO and TPR techniques. The obtained results showed that increasing nickel loading decreased the BET surface area and increased the catalytic activity and amount of deposited carbon. In addition, the effect of gas hourly space velocity （GHSV） and feed ratio were studied.

关键词： nickel catalyst MgO modifier syngas dry reforming coke formation

Ni catalysts supported on nanocrystalline magnesium oxide for syngas production by CO_2 reforming of CH_4

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Journal of Natural Gas Chemistry 2011年第2期20卷 198-203页

作者： Fereshteh Meshkani mehran rezaei Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan

CO2 reforming of methane （CDRM） was carried out over MgO supported Ni catalysts with various Ni loadings. The preparation of MgO supported Ni catalysts via surfactant-assisted precipitation method led to the formation of a nanocrystalline carrier for nickel catalysts. The synthesized samples were characterized by XRD, N2 adsorption-desorption, H2 chemisorption, TPR, TPO and SEM techniques. It was found that the high catalytic activity and stability of the prepared catalysts could be attributable to high dispersion of reduced Ni species and basicity of support surface. In addition, the effect of feed ratio, nickel loading and GHSV on the catalytic performance of CDRM over the catalysts were investigated.

关键词： nanocrystalline MgO nickel catalyst dry reforming syngas

Selective methanation of carbon monoxide in hydrogen rich stream over Ni/CeO_2 nanocatalysts

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Journal of Rare Earths 2015年第6期33卷 619-628页

作者： Behzad Nematollahi mehran rezaei Ebrahim Nemati Lay Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan

In the present work, selective methanation of carbon monoxide in hydrogen rich stream was investigated over Ni/CeO2 nanocatalysts. The obtained results revealed that increasing in nickel loading decreased the BET surface area, pore vohune and nickel dispersion. The 25%Ni/CeO2 with a NiO crystal size of 12 nm exhibited the highest activity in CO methanation reaction and reached to maximum CO conversion and CH4 selectivity at temperatures above 230 ℃. The catalytic results revealed that CO selective methanation well progressed at lower temperatures while CO2 methanation was completely suppressed until CO conversion reached to maximum value.

关键词： methanation nickel cerium oxide high surface area carbon monoxide rare earths

CH_4 reforming with CO_2 for syngas production over La_2O_3 promoted Ni catalysts supported on mesoporous nanostructured γ-Al_2O_3

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Journal of Energy Chemistry 2014年第4期23卷 435-442页

作者： Narges Habibi mehran rezaei Nasrollah Majidian Mahmood Anache Faculty of Engineering Tehran North Branch Islamic Azad UniversityTehran P.O.Box 166793 4783 Iran Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of KashanKashan P.O.Box 873175 1117 Iran Sarv Oil&Gas Industries Development Company Tehran P.O.Box 199367 3451 Iran

Nanostructured -y-A12O3 with high surface area and mesoporous structure was synthesized by sol-gel method and employed as catalyst support for nickel catalysts in methane reforming with carbon dioxide. The prepared samples were characterized by XRD, N2 adsorption-desorption, TPR, TPO, TPH, NH3-TPD and SEM techniques. The BET analysis showed a high surface area of 204 m2.g-1 and a narrow pore-size distribution centered at a diameter of 5.5 nm for catalyst support. The BET results revealed that addition of lanthanum oxide to aluminum oxide decreased the specific surface area. In addition, TPR results showed that addition of lanthanum oxide increased the reducibility of nickel catalyst. The catalytic evaluation results showed an increase in methane conversion with increasing lanthanum oxide to 3 mol% and further increase in lanthanum content decreased the catalytic activity. TPO analysis revealed that the coke deposition decreased with increasing lanthanum oxide to 3 mol%. SEM and TPH analyses confirmed the formation of whisker type carbon over the spent catalysts. Addition of steam and Oxide to drv reformin feed increased the methane conversion and led to carbon free ooeration in combined orocesses.

关键词： nanostructured γ-A12O3 nickel catalyst dry reforming lanthanum oxide

Optimization of preparation conditions of Fe-Co nanoparticles in low-temperature CO oxidation reaction by taguchi design method

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Journal of Natural Gas Chemistry 2012年第4期21卷 415-420页

作者： Abolfazl Biabani mehran rezaei Zohreh Fattah Catalyst and Advanced Materials Research Laboratory Chemical Engineering DepartmentFaculty of EngineeringUniversity of KashanKashan P.O.Box ***Iran Institute of Nanoscience and Nanotechnology University of KashanKashan P.O.Box ***Iran

Mixed iron-cobalt oxide （Co/Fe molar ratio = 1/5） are prepared using a simple co-precipitation procedure and studied for the catalytic oxidation of carbon monoxide. In particular, the effects of a range of preparation variables such as pH value when precipitation, aging temperature, precipitation agent type and aging time are investigated on the catalytic performance of synthesized Fe-Co oxides in CO oxidation reaction. In addition, the preparation factors were optimized by Taguchi design method. The optimized sample was characterized by XRD, N2 adsortion/desorption, TEM and TGA/DTA techniques. The results reveal that the optimized sample shows a mesoporous structure with a narrow pore size distribution centered in the range of 2-7 nm. The sample prepared under optimized conditions has high activity and stability toward removal of carbon monoxide at lower temperatures. It is shown that different preparation variables influence the catalytic performance of Fe-Co oxide in CO oxidation reaction.

关键词： Fe Co nanoparticles experimental design CO oxidation

Preparation of nanocrystalline γ-Al_2O_3 catalyst using different procedures for methanol dehydration to dimethyl ether

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Journal of Natural Gas Chemistry 2011年第3期20卷 334-338页

作者： Ahmad Reza Keshavarz mehran rezaei Fereydoon Yaripour Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan Catalyst Research Group Petrochemical Research & Technology Company National Petrochemical Company (NPC)

A series of nanocrystalline γ-alumina are synthesized by different procedures, namely, thermal decomposition method （sample A）, precipita-tion method （sample B） and sol-gel method using sucrose and hexadecyltrimethyl ammonium bromide （CTAB） as templates （samples C and D, respectively）. Textural and acidic properties of γ-alumina samples are characterized by XRD, N2 adsorption-desorption and NH3-TPD techniques. Vapor-phase dehydration of methanol into dimethyl ether is carried out over these samples. Among them, sample C shows the highest catalytic activity. NH3-TPD analysis reveals that the sample with smaller crystallite size possesses higher concentration of medium acidic sites and consequently higher catalytic activity. Thermal decomposition method leads to decrease in both surface area and moderate acidity, therefore it is the cause of lower catalytic activity.

关键词： methanol dehydration dimethyl ether gama alumina sol-gel

CO_2 reforming of methane over nickel catalysts supported on nanocrystalline MgAl_2O_4 with high surface area

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Journal of Natural Gas Chemistry 2012年第2期21卷 200-206页

作者： Narges Hadian mehran rezaei Zeinab Mosayebi Fereshteh Meshkani Institute of Nanoscience and Nanotechnology University of Kashan Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan

In this paper dry reforming of methane （DRM） was carried out over nanocrystalline MgAl2O4-supported Ni catalysts with various Ni loadings. Nanocrystalline MgAl2O4 spinel with high specific surface area was synthesized by a co-precipitation method with the addition of pluronic P123 triblock copolymer as surfactant, and employed as catalyst support. The prepared samples were characterized by X-ray diffraction （XRD）, N2 adsorption, H2 chemisorption, temperature-programmed reduction （TPR）, temperature-programmed oxidation （TPO）, temperature- programmed desorption （TPD） and transmission and scanning electron microscopies （TEM, SEM） techniques. The obtained results showed that the catalyst support has a nanocrystalline structure （crystal size： about 5 nm） with a high specific surface area （175 m2 g-1） and a mesoporous structure. Increasing in nickel content decreased the specific surface area and nickel dispersion. The prepared catalysts showed high catalytic activity and stability during the reaction. SEM analysis revealed that whisker type carbon deposited over the spent catalysts and increasing in nickel loading increased the amount of deposited carbon. The nickel catalyst with 7 wt% of nickel showed the highest catalytic activity.

关键词： dry reforming nickel catalysts magnesium aluminate

Thermodynamic analysis of combined reforming process using Gibbs energy minimization method: In view of solid carbon formation

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Journal of Natural Gas Chemistry 2012年第6期21卷 694-702页

作者： Behzad Nematollahi mehran rezaei Ebrahim Nemati Lay Majid Khajenoori Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan Energy Research Institute University of Kashan

Thermodynamic analysis was applied to study combined partial oxidation and carbon dioxide reforming of methane in view of carbon formation. The equilibrium calculations employing the Gibbs energy minimization were performed upon wide ranges of pressure （1-25 atm）, temperature （600-1300 K）, carbon dioxide to methane ratio （0-2） and oxygen to methane ratio （0-1）. The thermodynamic results were compared with the results obtained over a Ru supported catalyst. The results revealed that by increasing the reaction pressure methane conversion decreased. Also it was found that the atmospheric pressure is the preferable pressure for both dry reforming and partial oxidation of methane and increasing the temperature caused increases in both activity of carbon and conversion of methane. The results clearly showed that the addition of O2 to the feed mixture could lead to a reduction of carbon deposition.

关键词： combined reforming carbon deposition chemical equilibrium Gibbs energy minimization method thermodynamic analysis

介孔Fe-Cu复合金属氧化物纳米粉催化剂催化低温CO氧化（英文）

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催化学报 2015年第10期36卷 1711-1718页

作者： Ehsan Amini mehran rezaei 喀山大学纳米科技研究所工程学院化工系催化剂与先进材料研究实验室

以环氧丙烷为凝胶剂,采用简便低廉的无表面活性剂的溶胶-凝胶法制备了一系列不同Cu/Fe摩尔比的高比表面积介孔Fe-Cu复合氧化物纳米粉末.运用微反应器-色谱体系考察了它们在低温CO氧化反应中的催化性能.采用X射线衍射、N2吸附-脱附、热重... 详细信息

以环氧丙烷为凝胶剂,采用简便低廉的无表面活性剂的溶胶-凝胶法制备了一系列不同Cu/Fe摩尔比的高比表面积介孔Fe-Cu复合氧化物纳米粉末.运用微反应器-色谱体系考察了它们在低温CO氧化反应中的催化性能.采用X射线衍射、N2吸附-脱附、热重-差热分析、程序升温还原、傅里叶变换红外光谱和透射电镜对所制样品进行了表征.结果表明,这些介孔Fe-Cu复合氧化物催化剂具有纳米晶结构、窄的孔径分布和高的比表面积,在低温CO氧化反应中表现出高的活性和稳定性.CuO的添加影响了Fe2O3的结构和催化性能.当CuO含量为15 mol%时,催化剂具有最高的比表面积和催化活性,在低温CO氧化反应中表现出较高的催化稳定性.

关键词：氧化铁氧化铜金属氧化物催化剂介孔纳米粉一氧化碳氧化溶胶-凝胶法