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Mechanistic aspects of facet-dependent CH_(4)/C_(2+)selectivity over aχ-Fe_(5)C_(2)Fischer-Tropsch catalyst

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Green Energy & Environment 2022年第3期7卷 449-456页

作者： Thanh Hai Pham Junbo cao Nan Song yueqiang cao Bingxu Chen Gang Qian Xinggui Zhou De Chen Xuezhi Duan State Key Laboratory of Chemical Engineering East China University of Science and Technology130 Meilong RoadShanghai200237China Vietnam Institute for Tropical Technology and Environmental Protection 57A Truong Quoc DungHo Chi MinhViet Nam Department of Chemical Engineering Norwegian University of Science and TechnologyN-7491TrondheimNorway

Structure-performance relationship is a complex issue in iron-catalyzed Fischer-Tropsch synthesis,and it is not easy to elucidate it by experimental ***-principle calculation is a powerful method for explaining experimental results and guiding catalyst *** this study,we investigated the reaction mechanisms of CH_(4)formation and C-C coupling on fourχ-Fe_(5)C_(2)surfaces and established the kinetic equations to compare the rates of CH_(4)formation and C_(1)+C_(1)coupling reactions and determine the CH_(4)/C_(2+)*** results show that the geometry of theχ-Fe_(5)C_(2)surfaces has little effect on the formation rate of CH_(4);however,the C_(1)+C_(1)coupling reactions are significantly affected by the surface *** C_(1)+C_(1)coupling reaction rates on the terraced-like(510)and(021)surfaces are much higher than those on the stepped-like(001)and(100)*** on these results,we established a Brùnsted-Evans-Polanyi(BEP)relationship between the effective barrier difference for CH_(4)formation and C_(1)+C_(1)coupling(ΔE_(eff))and the adsorption energy of C+4H(ΔE_(C+4H))onχ-Fe_(5)C_(2)surfaces.ΔE_(C+4H)can be used as a descriptor for CH_(4)/C_(2+)selectivity on different surfaces ofχ-Fe_(5)C_(2).

关键词： selectivity catalyst coupling

Understanding the effects of electrode meso-macropore structure and solvent polarity on electric double layer capacitors based on a continuum model

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Chinese Journal of Chemical Engineering 2022年第10期50卷 423-434页

作者： Haotian Lu Jinghong Zhou yueqiang cao Tongxin Shang Guanghua Ye Quan-Hong Yang Xinggui Zhou State-Key Laboratory of Chemical Engineering East China University of Science of TechnologyShanghai 200237China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou 350207China Nanoyang Group State Key Laboratory of Chemical EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300350China

The structures of electrode meso-macropore and the solvent polarity are the crucial factors dominating the performance of the electric double layer capacitors(EDLCs),but their impacts are usually tangled and difficult to decouple and *** the effects of electrode meso-macropore structure and solvent polarity on the specific capacitance of an EDLC are quantitatively investigated using a steady-state continuum *** simulation results indicate the specific capacitances are significantly affected by the meso-macropore surface *** specific capacitances significantly decrease for both convex surface structures but obviously increase for both concave surface structures,with the increase of curvature radius from 1 to 20 *** for solvents,the polar solvent with high saturated dielectric permittivity improves the capacitance ***,the electrode meso-macropore structure is of more concern compared with solvent polarity when aiming at enhancing the specific *** results provide fundamentals for the rational design of porous electrodes and polar electrolytes for EDLCs.

关键词： Electric doublelayercapacitors Numerical simulation Meso-macropore Electrolytes Saturated dielectricpermittivity

Platelet carbon nanofibers as support of Pt-CoO electrocatalyst for superior hydrogen evolution

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Journal of Energy Chemistry 2021年第1期30卷 33-40,I0002页

作者： Jie Gan Zikun Huang Wei Luo Wenyao Chen yueqiang cao Gang Qian Xinggui Zhou Xuezhi Duan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Exploration of cost-effective Pt/C catalysts has been a significant issue for electrochemical hydrogen evolution reaction(HER) toward sustainable energy conversion and ***,we report a fabrication strategy by employing platelet carbon nanofibers(p-CNF) as the support to immobilize Pt-CoO HER electrocatalyst using atomic layer deposition *** edge-rich p-CNF support is found to act as the anchoring sites of Pt nanoparticles and favorably capture electrons from Pt to yield electron-deficient Pt surfaces for the boosted ***,the sequential growth of CoO onto the Pt/p-CNF catalyst elaborately constructs the Pt-CoO interface and facilitates the electron transfer from Pt to CoO,which further enhances the HER *** advantages endow the fabricated Pt-CoO/p-CNF catalyst with the superior HER activity,e.g.,a very low overpotential of 26 mV at the current density of 10 mA·cm-2 and a mass activity of 4.42 A·mgPt-1at the overpotential of 30 mV,18.8 times higher than that of the commercial20 wt% Pt/C *** insights reported here could shed light on for the fabrication of cost-effective Pt-based composite HER catalysts.

关键词： Hydrogen evolution Electrocatalysts Platelet carbon nanofibers Pt-CoO catalyst Atomic layer deposition

Structural and Kinetics Understanding of Support Effects in Pd-Catalyzed Semi-Hydrogenation of Acetylene

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Engineering 2021年第1期7卷 103-110页

作者： yueqiang cao Xiaohu Ge Yurou Li Rui Si Zhijun Sui Jinghong Zhou Xuezhi Duan Xinggui Zhou State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai 201800China

In this study,the support effects on the Pd-catalyzed semi-hydrogenation of acetylene have been investigated from the structural and kinetic *** to the results of kinetic analysis and X-ray photoelectron spectroscopy,hydrogen temperature-programmed reduction,temperature-programmed hydride decomposition,and in situ X-ray diffraction measurements,using carbon nanotubes as support for Pd nanocatalysts with various sizes instead of a-Al_(2)O_(3) decreases the Pd^(0)3d binding energy and suppresses the formation of undesirable palladium hydride species,thus increasing the ethylene ***,X-ray absorption spectroscopy,high-resolution transmission electron microscopy,and C_(2)H_(4) temperature-programmed desorption studies combined with density-functional theory calculations reveal the existence of a unique Pd local environment,containing subsurface carbon atoms,that produces positive geometric effects on the acetylene conversion ***,tailoring the Pd local environment and electronic properties represents an effective strategy for the fabrication and design of highly active and selective Pd semi-hydrogenation catalysts.

关键词： Acetylene semi-hydrogenation Reaction kinetics Support effects Electronic effects Pd local environment

Unleash electron transfer in C–H functionalization by mesoporous carbon-supported palladium interstitial catalysts

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National Science Review 2021年第4期8卷 154-166页

作者： Xiaorui Zhao yueqiang cao Linlin Duan Ruoou Yang Zheng Jiang Chao Tian Shangjun Chen Xuezhi Duan De Chen Ying Wan Key Laboratory of Resource Chemistry of Ministry of Education Shanghai Key Laboratory of Rare Earth Functional MaterialsDepartment of Chemistry Shanghai Normal University State Key Laboratory of Chemical Engineering East China University of Science and Technology Shanghai Synchrotron Radiation Facility Zhangjiang National Lab Shanghai Advanced Research Institute Chinese Academy of Sciences Department of Chemical Engineering Norwegian University of Science and Technology

The functionalization of otherwise unreactive C–H bonds adds a new dimension to synthetic chemistry,yielding useful molecules for a range of applications. Arylation has emerged as an increasingly viable strategy for functionalization of heteroarenes which constitute an important class of structural moieties for organic materials. However, direct bisarylation of heteroarenes to enable aryl-heteroaryl-aryl bond formation remains a formidable challenge, due to the strong coordination between heteroatom of N or S and transitional metals. Here we report Pd interstitial nanocatalysts supported on ordered mesoporous carbon as catalysts for a direct and highly efficient bisarylation method for five-membered heteroarenes that allows for green and mild reaction conditions. Notably, in the absence of any base, ligands and phase transfer agents, high activity(turn-over frequency, TOF, up to 107 h-1) and selectivity(>99%) for the2,5-bisarylation of five-membered heteroarenes are achieved in water. A combination of characterization reveals that the remarkable catalytic reactivity here is attributable to the parallel adsorption of heteroarene over Pd clusters, which breaks the barrier to electron transfer in traditional homogenous catalysis and creates dual electrophilic sites for aryl radicals and adsorbate at C2 and C5 positions. The d-band filling at Pd sites shows a linear relationship with activation entropy and catalytic activity. The ordered mesopores facilitate the absence of a mass transfer effect. These findings suggest alternative synthesis pathways for the design, synthesis and understanding of a large number of organic chemicals by ordered mesoporous carbon supported palladium catalysts.

关键词： palladium interstitial catalyst ordered mesoporous carbon direct bisarylation multi-site electron transfer d-charge gain

Active sites and reaction mechanism for N-doped carbocatalysis of phenol removal

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Green Energy & Environment 2020年第4期5卷 444-452页

作者： Mingjie Zhang Chen Han Wenyao Chen Wei Luo yueqiang cao Gang Qian Xinggui Zhou Xiaoguang Duan Shaobin Wang Xuezhi Duan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China WA School of Mines:Minerals Energy and Chemical EngineeringCurtin UniversityPerthWestern Australia 6845Australia School of Chemical Engineering The University of AdelaideAdelaideSouth Australia 5005Australia

Heteroatom-doping of carbocatalysts has been a powerful strategy to remarkably enhance the catalytic ***,the underlying nature of N promotional effects on peroxymonosulfate(PMS)activation for phenol removal is understood by combining kinetics analysis with multiple techniques.A strategy using mixed acid oxidation of carbon nanotube(CNT)followed by NH3 treatment is employed to yield a series of catalysts with different N-doping contents but similar fraction of sp^(2)-hybridized carbon and defective degree,endowing with a chance to discriminate the dominant N-containing active *** multi-sites kinetics analysis suggests the graphitic N-containing sites as the dominant active *** mechanism of the surface-bound reactive species is also discriminated as the dominant reaction *** insights reported here could provide the methodology to fundamentally understand the heteroatom-doping effects of carbocatalysis.

关键词： Phenol removal Carbocatalysis Multi-sites kinetics analysis Graphitic N-Containing sites Surface-bound reactive species

Mechanistic insights into the active intermediates of 2,6-diaminopyridine dinitration

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Chinese Journal of Chemical Engineering 2023年第4期56卷 160-168页

作者： Junao Zhu Zhirong Yang Yuanhan Chen Mingming Chen Zhen Liu yueqiang cao Jing Zhang Gang Qian Xinggui Zhou Xuezhi Duan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China

Mechanistic understanding of the active intermediates of 2,6-diaminopyridine(DAP) dinitration in the concentrated nitric-sulfuric acid system is of crucial importance for the selectivity control of target product, i.e., 2,6-diamino-3,5-dinitropyridine(DADNP). The active intermediates determining the product selectivity are theoretically studied. The HSO_(4)^(-)-NO_(2)^(+) complex is proposed as the dominant active nitrating intermediate for the first time, which shows low energy barrier(i.e., 10.19 kcal·mol^(-1),1 kcal = 4.186 k J) for direct dinitration of DAP to DADNP. The formed water during the reaction results in not only the formation of less active SO_(4)^(2-)-NO_(2)^(+) complex, but also the occurance of DAP sulfonation(DAP-SO_(3)H intermediate)to facilitate the formation of mononitration byproduct. Meanwhile, the accompanied thermal effects cause the generation of undesirable pyridine-NHNO_(2) intermediate, which is difficult to be rearranged to yield DADNP, inhibiting the reaction and thus giving low DAP conversion. The insights reported here elucidates the importance of thermal effects elimination and water content control, confirmed experimentally in the batch-and micro-reaction systems.

关键词： 2,6-Diaminopyridine Nitration mechanism Active intermediates Thermal effects Negative water effects

Poisoning effect of polyvinyl chloride on the catalytic pyrolysis of mixed plastics over zeolites

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Science China Chemistry 2024年第7期67卷 2265-2273页

作者： Jiangchun Yuan Wenjie Wang Weixiao Sun Zhirong Yang yueqiang cao Wenyao Chen Xiaohu Ge Gang Qian Xiang Feng Xuezhi Duan Xinggui Zhou Kevin M.Van Geem Jing Zhang State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China Laboratory for Chemical Technology(LCT) Department of MaterialsTextiles and Chemical EngineeringFaculty of Engineering&ArchitectureGhent UniversityZwijnaarde B-9052Belgium State Key Lab of Heavy Oil Processing China University of PetroleumQingdao 266580China

Nowadays,the chemical recycling is applied for only 1%of total waste plastics,largely due to contaminants in plastic waste and difficulty in product *** the major contaminant,polyvinyl chloride(PVC)often forms corrosive hydrogen chloride(HCl)during the chemical recycling,which may cause severe catalyst deactivation and equipment ***,the investigation on catalytic pyrolysis(the major route for plastics chemical recycling)of the PVC containing mixed plastics has been rarely ***,catalytic co-pyrolysis of PVC and polyethylene(PE)was studied over an aromatization catalyst,Pt/ZSM-5,since the basic building block aromatics are desired products from plastics chemical *** poisoning effect of PVC vapor on the catalyst stability was explored by collective efforts of thorough product analysis and catalyst *** was found that the HCl evolving from PVC has an autocatalytic effect that promotes the scission of dehydrochlorinated PVC,resulting in the high yield of benzene and acetylene from *** the other hand,the presence of PVC suppressed the aromatics formation from PE,largely due to the poisoning effect of PVC-derived HCl on the Pt/*** deactivation is irreversible as evidenced by the decreased zeolite crystallinity and the loss of strong acid sites that are key to the aromatization,possibly due to the removal of framework Al upon the interaction with *** modification with octadecylphosphonic acid only slightly alleviated the PVC poisoning *** insights on the PVC poisoning of zeolite catalysts provided in this work may guide the process design of chemical recycling of PVC containing waste plastics.

关键词： polyvinyl chloride polyethylene zeolite aromatics deactivation

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催化剂制备方法对Ni-Ag/SiO_(2)催化草酸二甲酯加氢制乙醇酸甲酯性能的影响

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燃料化学学报（中英文） 2024年第10期52卷 1495-1505页

作者：方笛罗祖伟曹约强周静红李伟华东理工大学化学工程联合国家重点实验室上海200237 华东理工大学化工学院上海200237

本研究采用均匀沉淀-浸渍和浸渍-浸渍两种分步法分别制备了Ni-Ag/SiO_(2)-p和Ni-Ag/SiO_(2)-i两种Ni-Ag双金属催化剂,用于催化草酸二甲酯(DMO)选择性加氢制乙醇酸甲酯(MG)。利用X射线衍射、红外光谱、透射电镜、N_(2)物理吸附、程序升... 详细信息

本研究采用均匀沉淀-浸渍和浸渍-浸渍两种分步法分别制备了Ni-Ag/SiO_(2)-p和Ni-Ag/SiO_(2)-i两种Ni-Ag双金属催化剂,用于催化草酸二甲酯(DMO)选择性加氢制乙醇酸甲酯(MG)。利用X射线衍射、红外光谱、透射电镜、N_(2)物理吸附、程序升温脱附实验和X射线光电子能谱表征技术对两种催化剂进行了系统的表征和结构解析,发现催化剂的制备方法对双金属催化剂的结构和性能有着重要影响,Ni-Ag/SiO_(2)-p催化剂中由于层状硅酸镍结构的存在,Ag、Ni活性物种的金属分散度相比于Ni-Ag/SiO_(2)-i催化剂更高,这促进了反应物H_(2)和DMO的吸附与活化;催化剂性能评价结果表明,均匀沉淀-浸渍法制备的Ag负载量仅为0.48%的Ni-Ag/SiO_(2)-p催化剂显著提升了DMO加氢活性,在220℃、2.0 MPa、液时空速0.5 h^(−1)、氢酯比50的条件下,DMO转化率和MG选择性达到了99.1%和87.6%。研究结果可为设计和优化DMO加氢制MG催化剂提供一定借鉴。

关键词：草酸二甲酯加氢催化剂制备乙醇酸甲酯