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Rare earth modified Ni-Si catalysts for hydrogen production from methane decomposition

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Journal of Rare Earths 2014年第8期32卷 709-714页

作者：于瀛崔梅生李明来赵娜龙志奇施用晞 National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals and Grirem Advanced Materials Co.Ltd. Science College Beijing University of Chemical Technology

Different rare earth （RE=La, Ce, Pr, Nd, Sm, Y） and Cu modified nickel catalysts for hydrogen production from meth-ane decomposition were synthesized by a sol-gel process and method. The catalysts were characterized or analyzed through Brumauer-Emmett-Teller （BET）, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） techniques. And the hydrogen production performance was also evaluated by a fixed-bed and micro-reaction technique with CH4→C＋H2 as a probe reaction. The results showed that rare earth modification had played a great role for nickel catalysts, for example, smaller nickel particles, good thermal stability, high activity, etc. La was the best additive among rare earth modification. The SEM of rare earth modified catalysts showed ordered flower-like structure and rare earth modification made the nickel particles move to the surface of catalysts. In addition, the SEM of nano-carbons was also changed by rare earth modification with long, narrow nano-carbon fibers or tubes obtained. Solid carbon formation was prevented by rare earth modification.

关键词： rare earth modification Ni-Si catalyst hydrogen production methane decomposition

Growth of Aligned Carbon Nanotubes on Large Scale by methane decomposition with Deactivation Inhibitor

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Journal of Natural Gas Chemistry 2007年第4期16卷 382-388页

作者： Hao Yu Zhili Li Cheng Zhang Feng Peng Hongjuan Wang School of Chemical and Energy Engineering South China University of Technology Guangzhou 510650 Guangdong China

The effects of additives containing iron or nickel during chemical vapor deposition （CVD） on the growth of carbon nanotubes （CNTs） by methane decomposition on Mo/MgO catalyst were investigated. Ferrocene and nickel nitrate were introduced as deactivation inhibitors by in-situ evaporation during CVD. The precisely controlled in-situ introduction of these inhibitors increased the surface renewal of catalyst, and therefore prevented the catalyst from deactivation. Using this method, aligned multi-walled CNTs with parallel mesopores can be produced on a large scale.

关键词： aligned carbon nanotubes chemical vapor deposition deactivation inhibitor methane decomposition Mo/MgO catalyst ferrocene nickel nitrate

Preparation of mesoporous activated carbons from coal liquefaction residue for methane decomposition

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Journal of Natural Gas Chemistry 2012年第6期21卷 759-766页

作者： Jianbo Zhang Lijun Jin Shengwei Zhu Haoquan Hu State Key Laboratory of Fine Chemicals Institute of Coal Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 116024LiaoningChina

Mesoporous activated carbons were prepared from direct coal liquefaction residue （CLR） by KOH activation method, and the experiments were carried out to investigate the effects of KOH/CLR ratio, solvent for mixing the CLR and KOH, and carbonization procedure on the resultant carbon texture and catalytic activity for catalytic methane decomposition （CMD）. The results showed that optimal KOH/CLR ratio of 2 ： 1; solvent with higher solubility to KOH or the CLR, and an appropriate carbonization procedure are conductive to improving the carbon pore structure and catalytic activity for CMD. The resultant mesoporous carbons show higher and more stable activity than microporous carbons. Additionally, the relationship between the carbon textural properties and the catalytic activity for CMD was also discussed.

关键词： mesoporous activated carbon KOH methane decomposition coal liquefaction residue hydrogen

Influences of reaction conditions on methane decomposition over non-supported Ni catalyst

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Journal of Natural Gas Chemistry 2011年第4期20卷 339-344页

作者： Wei Zhang Qingjie Get Hengyong Xu Laboratory of Applied Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 Liaoning China Chemistry and Chemical Eneineerine School of Northeastern Petroleum University Daqing 163318 Heilongiiang China

Effects of reaction temperature and methane gas hourly space velocity （GHSV） on methane decomposition over non-supported Ni catalyst have been investigated in this *** molecules activation,Ni particles growth and nano-carbon diffusion were the main factors influencing methane decomposition stability of non-supported *** results of methane decomposition activity test on the non-supported Ni catalyst showed that the prepared non-supported Ni could exhibit a good methane decomposition performance with 273 gC/gNi and 2667 molH2/molNi at 500 -C and 45000 mL/（gcat h）.Scanning electron microscope （SEM）,X-ray powder diffraction （XRD） and temperature-programmed oxi- dation （TPO） have been carried out to characterize the used *** deposited carbon was carbon nanofibers,among which graphitic carbon formation increased with the reaction time of methane *** particle size was not the decisive factor during the carbon growing stage.

关键词： precipitate rinsing solvent NiO morphology non-supported Ni methane decomposition

Effect of surface structure on the catalytic behavior of Ni:Cu/Al and Ni:Cu:K/Al catalysts for methane decomposition

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Journal of Natural Gas Chemistry 2008年第4期17卷 374-382页

作者： S.Tajammul Hussain Sheraz Gul Muhammed Mazhar Dalaver H.Anjum Faical Larachi National Centre for Physics Quaid-i-Azam University Department of Chemistry Quaid-i-Azam University Department of Structural Biology University of Pittsburgh School of Medicine Department of Chemical Engineering University of Laval

methane decomposition using nickel, copper, and aluminum （Ni：Cu/Al） and nickel, copper, potassium, and aluminum （Ni：Cu：K/Al） modified nano catalysts has been investigated for carbon fibers, hydrogen and hydrocarbon production. X-ray photoelectron spectroscopy （XPS）, static secondary ion mass spectrometry （SSIMS）, thermal gravimetric analysis （TGA）, Fourier transform infrared （FT-IR）, secondary electron microscopy/X-ray energy dispersive （SEM-EDX）, and temperature programmed desorption （TPD） were used to depict the chemistry of the catalytic results. These techniques revealed the changes in surface morphology and structure of Ni, Cu, Al, and K, and formation of bimetallic and trimetallic surface cationic sites with different cationic species, which resulted in the production of graphitic form of pure carbon on Ni：Cu/Al catalyst. The addition of K has a marked effect on the product selectivity and reactivity of the catalyst system. K addition restricts the formation of carbon on the surface and increases the production of hydrogen and C2, C3 hydrocarbons during the catalytic reaction whereas no hydrocarbons are produced on the sample without K. This study completely maps the modified surface structure and its relationship with the catalytic behavior of both systems. The process provides a flexible route for the production of carbon fibers and hydrogen on Ni：Cu/Al catalyst and hydrogen along with hydrocarbons on Ni：Cu：K/Al catalyst. The produced carbon fibers are imaged using a transmission electron microscope （TEM） for diameter size and wall structure determination. Hydrogen produced is COx free, which can be used directly in the fuel cell system. The effect of the addition of Cu and its transformation and interaction with Ni and K is responsible for the production of CO/CO2 free hydrogen, thus producing an environmental friendly clean energy.

关键词： bimetallic catalysts methane decomposition carbon fibers hydrogen higher hydrocarbons

Preparation of bimetallic catalysts Ni-Co and Ni-Fe supported on activated carbon for methane decomposition

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Carbon Resources Conversion 2020年第1期3卷 190-197页

作者： Yajie Wang Yun Zhang Shun Zhao Jialong Zhu Lijun Jin Haoquan Hu State Key Laboratory of Fine Chemicals Institute of Coal Chemical EngineeringDalian University of TechnologyDalian 116024China

Bimetallic catalysts(Ni-Co/AC and Ni-Fe/AC)supported on activated carbon(AC)were prepared via one-step method from coal as AC precursor with the addition of metal salts by KOH *** effects of the introduction of second metal(Co or Fe)into Ni/AC on the textural structure of the resultant bimetallic catalysts and their catalytic performances for methane decomposition were *** results showed that active metals can be directly supported on AC by the reaction of metal species with carbon during the *** addition of Co or Fe to Ni/AC resulted in the decrease of specific surface area and pore *** increasing the loading of Co or Fe,metal alloys were formed and total surface area and pore volume declined,but the mesoporosity was *** Ni-Co/AC and Ni-Fe/AC catalysts exhibited better catalytic activity and stability for methane decomposition compared than Ni/*** introduction of Co mainly improved initial catalytic activity;however,Ni-Fe/AC catalyst showed better behaviors in terms of reducing the deactivation rate of Ni-based catalyst than Ni-Co/AC catalyst,which is relative with the formation of Ni-Fe alloy and carbon fibers over Ni-Fe/*** work provides a simple and efficient approach to improve catalytic performances of Ni-based catalyst for methane decomposition.

关键词： Activated carbon Ni-Co Ni-Fe methane decomposition Hydrogen Bimetallic

Catalytic decomposition of methane to produce hydrogen:A review

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Journal of Energy Chemistry 2021年第7期30卷 415-430页

作者： Zeyu Fan Wei Weng Jing Zhou Dong Gu Wei Xiao School of Resource and Environmental Sciences Hubei International Scientiﬁc and Technological Cooperation Base of Sustainable Resource and EnergyWuhan UniversityWuhan 430072HubeiChina College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power SourcesWuhan UniversityWuhan 430072HubeiChina The Institute for Advanced Studies Wuhan UniversityWuhan 430072HubeiChina

The increasing demands of hydrogen and the recent discovery of large reserves of methane have prompted the conversion of methane to *** challenges raised by intensive CO_(2) emission from the traditional conversion of methane have provoked emission-free hydrogen production from *** catalytic decomposition of methane(CDM) to produce hydrogen and advanced carbon hence comes into consideration due to the short process and environmental *** many researchers have made considerable progress in CDM research on the laboratory scale,CDM is still in its infancy in *** history of its development,fundamental mechanisms,and recent research progress in catalysts and catalytic systems are herein *** problems of catalytic interface degradation are reviewed,focusing on deactivation from coke deposition in the CDM *** introduction of a liquid phase interface which can in-situ remove carbon products provides a new strategy for this ***,the challenges and prospects for future research into novel CDM catalysts or catalyst systems are included.

关键词： Hydrogen production methane decomposition Metal-based catalysts Carbon-based catalysts Liquid catalyst

CO_x-Free Hydrogen and Carbon Nanofibers Produced from Direct decomposition of methane on Nickel-Based Catalysts

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Journal of Natural Gas Chemistry 2006年第4期15卷 253-258页

作者： Siang-Piao Chai Sharif Hussein Sharif Zein Abdul Rahman Mohamed School of Chemical Engineering Universiti Sains MalaysiaEngineering Campus Seri Ampangan14300 Nibong TebalSPS Penang Malaysia

Direct decomposition of methane was carried out using a fixed-bed reactor at 700 ℃ for the production of COx-free hydrogen and carbon nanofibers. The catalytic performance of NiO-M/SiO2 catalysts （where M=AgO, CoO, CuO, FeO, MnOx and MoO） in methane decomposition was investigated. The experimental results indicate that among the tested catalysts, NiO/SiO2 promoted with CuO give the highest hydrogen yield. In addition, the examination of the most suitable catalyst support, including Al2O3, CeO2, La2O3, SiO2, and TiO2, shows that the decomposition of methane over NiO-CuO favors SiOx support. Furthermore, the optimum ratio of NiO to CuO on SiO2 support for methane decomposition was determined. The experimental results show that the optimum weight ratio of NiO to CuO fell at 8：2 （w/w） since the highest yield of hydrogen was obtained over this catalyst.

关键词： methane decomposition hydrogen carbon nanofibers supported catalyst

Catalytic decomposition of CH_4 over Ni-Al_2O_3-SiO_2 catalysts:Influence of pretreatment conditions for the production of H_2

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Journal of Natural Gas Chemistry 2008年第2期17卷 113-119页

作者： Jangam Ashok Gangadhara Raju Padigapati Shiva Reddy Machiraju Subrahmanyam Akula Venugopal Catalysis and Physical Chemistry Division Indian Institute of Chemical TechnologyTarnakaHyderabadIndia-500 607

This article reports the production of COx free hydrogen and carbon nanofibers by the catalytic decomposition of methane over Ni-Al2O3-SiO2 catalysts. The influence of reaction temperature, pretreatment temperature, and effect of reductive pretreatment on the decomposition of methane activity is investigated. The physico-chemical characteristics of fresh and deactivated samples were characterized using BET-SA, XRD, TPR, SEM/TEM, CHNS analyses and correlated with the methane decomposition results obtained. The Ni-Al-Si （4 ： 0.5 ： 1.5） catalyst reduced with hydrazine hydrate produced better H2 yields of ca. 1815 mol H2/mol Ni than the catalyst reduced with 5% H2/N2.

关键词： in situ reduction Ni-Al2O3-SiO2 catalyst methane decomposition hydrogen production carbon nanofibers