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Elucidating the effect of barium halide promoters on La_(2)O_(3)/CaO catalyst for oxidative coupling of methane

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Journal of Energy Chemistry 2022年第10期31卷 49-59,I0003页

作者： Yue Wang Xiao Yang Fumin Yin Kai Zhang Hongfei Guo Guowei Wang Guiyuan Jiang Chunyi Li Xiaolin Zhu state key laboratory of heavy oil processing China University of PetroleumQingdao 266580ShandongChina state key laboratory of heavy oil processing China University of PetroleumBeijing 102249China

The industrialization of oxidative coupling of methane(OCM)is restricted by the low once through yield of C_(2)hydrocarbons.Recently,the halogen-assisted OCM process has been attempted to overcome this issue,but the reaction stability was poor due to the rapid loss of gas-phase halides or molten alkali halides.In this work,the barium salts,particularly barium halides(BaCl_(2)and BaF_(2)),were demonstrated to be efficient promoters to improve the OCM reactivity of La_(2)O_(3)/CaO catalyst by increasing both C_(2)selectivity and C_(2)H_(4)/C_(2)H_(6)ratio,and simultaneously achieving outstanding reaction stability.The promoting mechanism can be understood in two aspects.On the one hand,the introduction of barium salts increased the amount of surface electrophilic oxygen species,serving as the alkaline active sites for selective methane activation.On the other hand,the barium halide additives induced the in-situ formation of methyl halide intermediates facilitating C_(2)H_(6)dehydrogenation,and their intimate contact with catalyst substrate restricted the rapid halogen loss and thereby improved the catalytic stability.This work not only provides a class of efficient OCM catalyst,but also offers a highly stable halogen-assisted reaction strategy.

关键词： Oxidative coupling of methane La_(2)O_(3)/CaO catalyst Barium halide promoters Active oxygen species Methyl halide intermediates

Hydrate formation from liquid CO_(2) in a glass beads bed

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Chinese Journal of Chemical Engineering 2022年第3期35卷 185-191页

作者： Nan Li Jing-Yu Kan Chang-Yu Sun Guang-Jin Chen state key laboratory of heavy oil processing China University of Petroleum-Beijing at KaramayKaramay 834000China state key laboratory of heavy oil processing China University of PetroleumBeijing 102249China

CO_(2)sequestration in marine sediments as solid hydrates is a potential way to capture and store anthropogenic CO_(2).In this study,hydrate formation from liquid CO_(2)in marine sediments was simulated in a glass beads bed,and the factors affecting the kinetics of hydrate formation were investigated.The results indicated that the rapid initial hydrate formation with a high driving force always increases the mass transfer resistance,which slows down hydrate growth.The final ratio of water conversion is higher under conditions of low temperature and higher pressure.A smaller particle size is conductive to initial CO_(2)hydrate growth,but the water conversion ratio in a bed with larger particles is slightly higher.Compared with other factors,the change in water saturation has an obvious effect on the final water conversion.To inhibit the initial hydrate formation during the injection process,in this paper,a kinetic inhibitor is proposed for pre-injection into marine sediments.This work shows that at a low pressure,a lowconcentration inhibitor has an obvious inhibition effect on hydrate growth.However,at a high pressure,it is necessary to increase the concentration of inhibitor to produce an obvious inhibition effect.

关键词： Liquid CO_(2) Hydrate formation Sequestration Kinetic Water conversion

Low-concentration and multi-component NMHCs capture from oil field exhaust using porous ZIF-8/iso-hexadecane slurry

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Green Chemical Engineering 2024年第2期5卷 245-256页

作者： Kun Li Han Tang Jin Cai Chun Deng Bei Liu Yunlei Peng Changyu Sun Guangjin Chen state key laboratory of heavy oil processing China University of PetroleumBeijing102249China

Non-methane hydrocarbons(NMHCs)are a common type of volatile organic compounds(VOCs)pollutant in the petrochemical industry and have attracted widespread attention because of their adverse health effects and environmental impacts.In this paper,we report a new porous slurry formed with zeolitic imidazolate framework-8(ZIF-8)and iso-hexadecane to capture the low-concentration and multi-component NMHCs(mainly ethane(C_(2)H_(6)),propane(C_(3)H_(8)),and n-butane(n-C_(4)H_(10)))from the oil field exhaust.The sorption capacity of C_(2)H_(6)in the slurry is significantly higher than that of nitrogen(N_(2))and methane(CH_(4)).Moreover,the slurry demonstrated a clear advantage for C_(2)H_(6)over N_(2)and CH_(4)in competitive adsorption through the pressure-drop curves.In the NMHCs capture experiments,the C_(3)H_(8)and n-C_(4)H_(10)concentrations after purification can be reduced to below 100 ppm,while the C_(2)H_(6)concentration can reach approximately 180 ppm.More encouragingly,in the breakthrough tests,the slurry exhibits a perfect kinetic separation selectivity for multi-component NMHCs.Furthermore,to avoid structural collapse of ZIF-8 material during long-term use in acidic and wet environments,a certain amount of 2-methylimidazole was retained in the slurry as a protective agent in the material synthesis process.In this way,the ZIF-8 materials in the slurry can retain the stable characteristic structure in an aqueous and acidic environment and keep the capture capacity for NMHCs without degradation.We believe the porous ZIF-8/iso-hexadecane slurry is a promising capture agent for low-concentration and multi-component NMHCs with strong purification capacity and stability.

关键词： VOCs capture NMHCs capture MOFs ZIF-8 Porous slurry

Predictive methods for density and refractive index of naphthenic lubricating oils during solvent extraction process

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petroleum Science 2023年第3期20卷 1934-1946页

作者： Xiao-Ling Xu Tian-Qi Wang Guang-Huai Chen Jun-Wei Hou Yan-Sheng Liu state key laboratory of heavy oil processing China University of Petroleum(Bejing)at KaramayKaramayXinjiang834000China state key laboratory of heavy oil processing China University of Petroleum(Bejing)Bejing102200China

Lubricating oils are usually produced by solvent extraction to separate aromatics in order to achieve the desired specifications and better quality products.Among the different properties of lubricating oils,density and refractive index are some of the most important properties which can both be used for petroleum fluid characterization.Predictions of density and refractive index for naphthenic oils during solvent extraction by DMSO obtained by the pseudo-component approach and the quadratic correlation were both examined.The pseudo-component approach is a method to predict density and refractive index from composition while the latter merely relates density to refractive index.Results indicated that the predictions yielded by the pseudo-component method were in good agreement with experimental data for naphthenic oils.And the use of a function of refractive index(FRI_(20))as a pseudo-component property remarkably improved n_(20)predictions for the naphthenic mixtures.However,the density and refractive index predictions obtained by the quadratic correlation exhibited significantly higher de-viations for naphthenic oils than those for paraffinic oils.Thus a new modified correlation of the same functional form was proposed for naphthenic oils.The modification significantly improved predictions for naphthenic oils,which presented similar accuracy as the pseudo-component approach.And the previous correlation was still used for paraffinic oils.Additionally,effect of temperature on density and refractive index of naphthenic oils was examined.Results showed that the modified quadratic correlation was accurate for describing the relationship between density and refractive index of naphthenic oils at 20-90℃.The temperature dependence of density and refractive index for the raffinates and the extracts could be accurately described by the thermal coefficients for saturates and aromatics,respectively.Regarding the refractive index variation of the extracts with temperature,the empirical equation was proved to be a better opt

关键词： Density Refractive index Pseudo-components Paraffinic lubricating oils Naphthenic lubricating oils Solvent extraction

Influence of carbonization temperature on cobalt-based nitrogendoped carbon nanopolyhedra derived from ZIF-67 for nonoxidative propane dehydrogenation

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petroleum Science 2023年第1期20卷 559-568页

作者： Yu-Ming Li Zi-Ye Liu Qi-Yang Zhang Ya-Jun Wang Guo-Qing Cui Zhen Zhao Chun-Ming Xu Gui-Yuan Jiang state key laboratory of heavy oil processing China University of PetroleumBeijing102249China

Propylene is a significant basic material for petrochemicals such as polypropylene,propylene oxide,etc.With abundant propane supply from shale gas,propane dehydrogenation(PDH)becomes extensively attractive as an on-purpose propylene production route in recent years.Nitrogen-doped carbon(NC)nanopolyhedra supported cobalt catalysts were synthesized in one-step of ZIF-67 pyrolysis and investigated further in PDH.XPS,TEM and N_(2) adsorption-desorption were used to study the influence of carbonization temperature on as-prepared NC supported cobalt catalysts.The temperature is found to affect the cobalt phase and nitrogen species of the catalysts.And the positive correlation was established between Co0 proportion and space time yield of propylene,indicating that the modulation of carbonization temperature could be important for catalytic performance.

关键词： Propane dehydrogenation ZIF-67 Nitrogen-doped carbon Cobalt

Electrochemical synthesis of Ni doped carbon quantum dots for simultaneous fluorometric determination of Fe^(3+)and Cu^(2+)ion facilely

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Green Chemical Engineering 2023年第1期4卷 115-122页

作者： Siyuan Sun Yang Sun Fan Yang Sai Che Xiaoyun Zhang Ge Zhang Yongfeng Li state key laboratory of heavy oil processing China University of PetroleumBeijing102249China

A novel Ni doped carbon quantum dots(Ni-CQDs)fluorescence probe was synthesized by facile electrolysis of monoatomic Ni dispersed porous carbon(Ni–N–C).The obtained Ni-CQDs showed a high quantum yield of 6.3%with the strongest excitation and emission peaks of 360 nm and 460 nm,and maintained over 90%of the maximum fluorescence intensity in a wide p H range of 3–12.The metal ions detectability of Ni-CQDs was enhanced by Ni doping and functional groups modification,and the rapid and selective detection of Fe^(3+)and Cu^(2+)ions was achieved with Ni-CQDs through dynamic and static quenching mechanism,respectively.On one hand,the energy band gap of Ni-CQDs was regulated by Ni doping,so that excited electrons in Ni-CQDs were able to transfer to Fe^(3+)easily.On the other hand,the abundant functional groups promoted the generation of static quenching complexation between Cu^(2+)and Ni-CQDs.In metal ions detection,the linear quantitation range of Fe^(3+)and Cu^(2+)were 100–1000μM(R^(2)=0.9955)and 300–900μM(R^(2)=0.9978),respectively.The limits of detection(LOD)were calculated as 10.17 and 7.88μM,respectively.Moreover,the fluorescence quenched by Cu^(2+)could be recovered by EDTA2-due to the destruction of the static quenching complexation.In this way,NiCQDs showed the ability to identify the two metal ions to a certain degree under the condition of Fe^(3+)and Cu^(2+)coexistent.This work paves the way of facile multiple metal ion detection with high sensitivity.

关键词： Electrolysis Ni doped CQDs Fe^(3+)detection Cu^(2+)detection Ions distinction

Mo-doped CoP nanoparticles anchored on porous Co-N-C framework as an efficient bifunctional electrocatalyst for pH-universal water splitting

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Journal of Materials Science & Technology 2023年第35期166卷 58-66页

作者： Guohua Li Fan Yang Sai Che Hongchen Liu Neng Chen Jinxiu Qian Chunhui Yu Bo Jiang Mengxi Liu Yongfeng Li state key laboratory of heavy oil processing China University of PetroleumBeijing 102249China

Designing highly active and stable noble-metal-free electrocatalysts for water splitting over a wide pH range is critical yet remains significantly challenging.In this work,Mo-doped CoP nanoparticles(Mo-CoP)supported and enwrapped by porous single-atomic-Co doped carbon framework(Co-N-C)were designed and prepared by a simple one-pot pyrolysis method.The Mo-CoP/Co-N-C electrocatalyst exhibits superior performance with low overpotentials of only 45 mV for hydrogen evolution reaction(HER)and 201 mV for oxygen evolution reaction(OER)in 1 M KOH at 10 mA cm^(-2)current density.Such excellent catalytic activity can be ascribed to enhanced intrinsic activity,large surface area,and highly exposed active sites.Meanwhile,an extremely small overpotential of only 250 mV is required for a large current density of 500 mA cm^(-2)in HER,which exceeds the performance of benchmark 10%Pt/C.Besides,Mo-CoP/Co-N-C also exhibits superior HER performance in acidic and neutral mediums,with overpotentials of only 41 and 98 mV in 0.5 M H_(2)SO_(4),and 1 M PBS,respectively,thus achieving efficient water splitting at a wide pH range.The long-term stabilities are guaranteed with no significant decline of catalytic activities for more than 24 h in all electrolytes,which can be ascribed to the carbon layer encapsulation structure.Addition-ally,in overall water splitting,the electrocatalytic cell consisting of the as-synthesized Mo-CoP/Co-N-C only requires a cell voltage of 1.611 V at 100 mA cm^(-2)with excellent stability,exceeding that of the benchmark Pt/C||RuO(2) couple(1.645 V at 100 mA cm^(-2)).This work not only presents a highly efficient electrocatalyst for pH-universal water splitting but also provides a new perspective for the design and construction of transition metal catalysts with excellent stability.

关键词： Cobalt phosphide Mo doping Single atomic catalyst Water splitting pH-universal

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单原子合金的基本原理和催化应用

Science china Materials 2024年第1期67卷 1-17页

作者：孙晓辉宋杨姜桂元蓝兴英徐春明 state key laboratory of heavy oil processing China University of Petroleum(Beijing)Beijing 102249China

在惰性金属表面掺入原子级分散催化活性金属制备而成的单原子合金近年来引起了科研界的极大关注.单原子合金表面独特的几何和电子性质加速了反应物分子的解离并弱化了中间物种的吸附,使其在诸多催化反应中表现出高活性和高选择性.本文... 详细信息

在惰性金属表面掺入原子级分散催化活性金属制备而成的单原子合金近年来引起了科研界的极大关注.单原子合金表面独特的几何和电子性质加速了反应物分子的解离并弱化了中间物种的吸附,使其在诸多催化反应中表现出高活性和高选择性.本文总结了单原子合金的结构特征和催化反应性能的最新进展.我们首先列举了一系列单原子合金的可控合成方法,并进一步总结了高端表征技术,特别是原位光谱技术用于识别单原子合金中活性金属原子的几何和电子结构的方法.然后,我们结合多种催化反应,深入探究了单原子合金的几何与电子特性与催化性能之间的构效关系.最后探讨了单原子合金当前面临的挑战和未来的前景.

关键词：活性金属单原子电子特性表征技术原子级催化反应构效关系催化应用

High-efficiency separation and extraction of naphthenic acid from high acid oils using imidazolium carbonate ionic liquids

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Chinese Journal of Chemical Engineering 2022年第1期35卷 252-259页

作者： Fenghua Geng Rui Zhang Luo Wu Zheng Tang Han Liu Haiyan Liu Zhichang Liu Chunming Xu Xianghai Meng state key laboratory of heavy oil processing China University of PetroleumBeijing 102249China

N-alkyl imidazolium carbonate ionic liquids were employed to separate and recover naphthenic acid from model oils.The effects of the cationic and anionic structures of ionic liquids and operating conditions on the deacidification performance were investigated.The deacidification performance of traditional organic solvents was also investigated for comparison.The results indicated that the naphthenic acid could be completely removed from the model oil with a small mass ratio of ionic liquid to oil.The extracted naphthenic acid was regenerated with a recovery of up to 92%.In addition,imidazolium carbonate ionic liquids could be successfully regenerated and recycled.The mechanism of interaction between imidazole ionic liquids and the naphthenic acid molecules were explained by Gauss calculation.

关键词： Extraction Ionic liquid Naphthenic acid Recovery Computational chemistry