Xinhe Bao

Xiamen University, Amoy, Fujian, China

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Publications (430)2125.39 Total impact

  • Xuejun Xu · Qiang Fu · Xinhe Bao ·
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    ABSTRACT: Pt-Mo/SiO2 catalysts were prepared using impregnation-reduction methods. Mo-promoted Pt catalysts exhibit much higher water gas shift reaction activity at low temperatures than Pt/SiO2 catalysts. Various characterization methods including inductive coupled plasma atomic emission spectrometry, X-ray diffraction, transmission electron microscopy, X-ray absorption near edge spectrum, and X-ray photoelectron spectroscopy were applied to investigate the composition, structure and chemical state of the Pt-Mo/SiO2 catalysts. Our results indicate that the added Mo species effectively improves the dispersion of Pt nanoparticles and the synergistic effect between the Pt nanoparticles and surface MoOx species enhances the catalytic performance for the water gas shift reaction. Pt nanoparticles decorated with highly dispersed MoOx patches are found to be the active architecture.
    Chinese Journal of Catalysis 12/2015; 36(5):750-756. DOI:10.1016/S1872-2067(14)60294-1 · 1.96 Impact Factor

  • The Journal of Physical Chemistry C 11/2015; DOI:10.1021/acs.jpcc.5b09498 · 4.77 Impact Factor

  • Microporous and Mesoporous Materials 11/2015; DOI:10.1016/j.micromeso.2015.10.039 · 3.45 Impact Factor
  • Ting He · Pengju Ren · Xianchun Liu · Shutao Xu · Xiuwen Han · Xinhe Bao ·
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    ABSTRACT: The dynamic evolution of acetyl intermediates in the two different channels of H-mordenite (H-MOR) zeolite during dimethyl ether (DME) carbonylation is tracked by using in situ solid-state NMR spectroscopy under continuous-flow conditions. Thus, the reaction path via methyl acetate produced over active sites in 8 member ring (MR) channels, followed by diffusion into 12 MR channels, is proposed.
    Chemical Communications 10/2015; 51(94). DOI:10.1039/C5CC07201H · 6.83 Impact Factor
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    Yang Yang · Qiang Fu · Haobo Li · Mingming Wei · Jianping Xiao · Wei Wei · Xinhe Bao ·
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    ABSTRACT: Heterostructures of two-dimensional (2D) atomic crystals have attracted increasing attention while fabrication of the 2D stacking structures remains as a challenge. In this work, we present a route towards formation of the 2D heterostructures via confined growth of 2D adlayer underneath the other 2D overlayer. Taking hexagonal boron nitride (h-BN) monolayer on Ni(111) as a model system, both epitaxial and non-epitaxial h-BN islands have been identified on the Ni surface. Surface science studies combined with density function theory calculations reveal that the non-epitaxial h-BN islands interact weakly with the Ni(111) surface, which create 2D nano-space underneath the h-BN islands. An additional h-BN or graphene layer can be grown in the space between the non-epitaxial h-BN islands and Ni(111) surface, forming h-BN/h-BN bilayer structures and h-BN/graphene heterostructures. These results suggest that confined growth under 2D covers may provide an effective route to obtain stacks of 2D atomic crystals.
    ACS Nano 10/2015; DOI:10.1021/acsnano.5b05509 · 12.88 Impact Factor
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    ABSTRACT: Interlayer expansion using silylating agents to connect layer silicates to 3D framework structures has shown to be a versatile synthesis route to new crystalline, microporous frameworks. We demonstrate here that also Me cations can be introduced on the linker sites applying the same synthesis procedure. An acidic aqueous Fe-chloride solution was used in a hydrothermal reaction to convert the layered hydrous silicate precursor RUB-36 into an interlayer expanded zeolite, containing Fe at the linker sites, Fe-IEZ-RUB-36, Si19.14Fe0.86O38(OH)4. Structure analysis from powder X-ray data using the Rietveld technique confirmed that the porous framework is stable upon calcination and contains Fe on T-sites at the linker position. SEM-EDX analysis is in agreement with the analysis of the electron density maps showing that almost every other linker T-position is occupied by Fe-ions. The material crystallizes in the monoclinic space group Pm with a = 12.200(9) Å, b = 13.981(8) Å, c = 7.369(2) Å, and β = 106.9(1)°. Applying a similar synthesis procedure, the Sn-analog, Sn-IEZ-RUB-36, Si38.6Sn1.4O76(OH)8, has been obtained and structurally characterized. Despite its limited crystallinity, Rietveld analysis of the PXRD data set confirmed the materials framework topology and chemical composition (a = 23.856(14) Å, b = 14.103(7) Å, c = 7.412(7) Å, in SG Pnm21). We conclude, that the synthesis procedure is flexible and, meanwhile, has been extended to other metal cations such as Ti, Zn, Eu and Al leading to microporous materials with potentially active metal cations on well defined sites of the silicate framework.
    Microporous and Mesoporous Materials 10/2015; 222. DOI:10.1016/j.micromeso.2015.09.051 · 3.45 Impact Factor
  • Xiaoqi Chen · Dehui Deng · Xiulian Pan · Xinhe Bao ·
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    ABSTRACT: Fe-based catalyst is an outstanding candidate for the Fischer-Tropsch reaction to get light olefins from syngas directly. However, exposed Fe species are susceptible to sintering and coking, which lead to deactivation. Here, we demonstrate that Fe nanoparticles encapsulated in pod-like carbon nanotubes (Pod-Fe) can be used as an efficient Fischer-Tropsch catalyst to produce light olefins. It gave a higher selectivity of light olefins (45%) and high stability over 120 h reaction (P = 0.5 MPa, T = 320 ℃, CO:H2 = 1:2, gas hourly space velocity = 3500 h-1). A catalyst with exposed Fe particles on the outside of the Pod-Fe (FeOx/Pod-Fe) catalyst showed a selectivity of light olefins of 42%, but had a significantly lower stability due to the agglomeration of Fe nanoparticles and carbon deposition. These results indicated that the graphene shell of Pod-Fe played an important role in protecting the Fe particles and provided a rational way to enhance the activity and stability of Fe-based catalysts in high temperature reactions. © 2015, Dalian Institute of Chemical Physics, Chinese Academy of Sciences.
    Chinese Journal of Catalysis 09/2015; 36(9):1631-1637. DOI:10.1016/S1872-2067(15)60882-8 · 1.96 Impact Factor
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    ABSTRACT: SiO2 supported Pt-Ni bimetallic catalysts with different nickel loadings were prepared and their structural changes after redox treatments were studied by XRD, NMR, and EPR. It is found that the paramagnetic Ni species are mainly located on the surface of silica lattice. The relaxation of detected 29Si nuclei in our samples is mainly governed by a spin-diffusion mechanism. The paramagnetic effects are reflected in the spin-lattice relaxation of Q4 species, with the oxidized samples presenting faster relaxation rates than the corresponding reduced ones. Meanwhile the Q3 species, which are in close contact with the paramagnetic nickel centers, are "spectrally invisible". In reducing atmosphere Ni gradually diffuses into Pt NPs to form PtNi alloys. While under oxidization treatment, the alloyed Ni atoms migrate outward from the core of Pt NPs and are oxidized. The main EPR spectrum results from reduced nickel species, and the reduced samples show stronger EPR signal than the corresponding oxidized ones. However, in the reduced samples, the superparamagnetic or ferromagnetic metallic Ni particles were inside the PtNi NPs, making their influence on the 29Si relaxation in the SiO2 support weaker than the oxidized samples.
    The Journal of Physical Chemistry C 09/2015; 119(36):21219-21226. DOI:10.1021/acs.jpcc.5b06344 · 4.77 Impact Factor
  • Yanhong Zhang · Mingming Wei · Qiang Fu · Xinhe Bao ·
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    ABSTRACT: The interface between a two-dimensional (2D) atomic crystal and a metal surface can be regarded as a nanoreactor, in which molecule adsorption and catalytic reactions may occur. In this work, we demonstrate that oxygen intercalation and desorption occur at the interface between hexagonal boron nitride (h-BN) overlayer and Pt(111) surface by using near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS), photoemission electron microscopy, and low-energy electron microscopy. Furthermore, CO oxidation under the h-BN cover was also observed by NAP-XPS. The present results indicate that the nanospace under the 2D cover can be used for surface reactions, in which novel surface chemistry may be induced by the nanoconfinement effect. © 2015, Science China Press and Springer-Verlag Berlin Heidelberg.
    09/2015; 60(18). DOI:10.1007/s11434-015-0875-z
  • Jiayuan Li · Dunfeng Gao · Jing Wang · Shu Miao · Guoxiong Wang · Xinhe Bao ·
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    ABSTRACT: Replacing platinum for catalyzing hydrogen evolution reaction (HER) in acidic medium remains great challenges. Herein, we prepared few-layered MoS2 by ball milling as an efficient catalyst for HER in acidic medium. The activity of as-prepared MoS2 had a strong dependence on the ball milling time. Furthermore, Ketjen Black EC 300J was added into the ball-milled MoS2 followed by a second ball milling, and the resultant MoS2/carbon black hybrid material showed a much higher HER activity than MoS2 and carbon black alone. The enhanced activity of the MoS2/carbon black hybrid material was attributed to the increased abundance of catalytic edge sites of MoS2 and excellent electrical coupling to the underlying carbon network.
    Journal of Energy Chemistry 08/2015; 24(5). DOI:10.1016/j.jechem.2015.08.003 · 2.35 Impact Factor
  • Jinjing Li · Xiulian Pan · Xinhe Bao ·
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    ABSTRACT: Direct conversion of syngas into hydrocarbons with high selectivity remains a challenge. Herein, we report the synthesis of a core–shell-structured catalyst constituting Cr-Zn oxide as the core and SAPO-34 as the shell for the conversion of syngas into hydrocarbons with high selectivity. A SiO2 layer was sandwiched between the core and the shell to prevent damage to the core during shell synthesis. Furthermore, the intermediate SiO2 layer acted as a Si source for the formation of the shell. The prepared catalyst displayed considerably higher selectivity toward the production of C2–C4 hydrocarbons (66.9%) than that of methanol and methane. The findings show the potential of the prepared core–shell-structured catalyst in the one-step production of hydrocarbons, such as liquefied petroleum gas, from syngas. However, further optimization of the catalyst is necessary to achieve higher performance.
    Chinese Journal of Catalysis 07/2015; 36(7). DOI:10.1016/S1872-2067(14)60297-7 · 1.96 Impact Factor
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    ABSTRACT: Density functional theory (DFT) has been performed to characterize the structural stability and Lewis acidic properties of the T-COE-4 zeolites, in which the linked site between the layers is isomorphously substituted by the tetravalent Ti-, Sn-, or Zr- heteroatom. The effects of substitution energy and equilibrium geometry parameters on the stability of T-COE-4 are investigated. The computed Fukui function values and the adsorption of ammonia, pyridine, water and trimethylphosphine oxide molecules have been employed to predict the Lewis acid strength of the T-COE-4 zeolites. It is found that the smaller the O1-T-O2 bond angle is, the more difficult is to form the regular tetrahedral unit. The substitution energies at the linker position increase in the following sequence: Ti-COE-4 < Sn-COE-4 < Zr-COE-4. The incorporation of Ti-, Sn-, or Zr-heteroatom enhances the Lewis acidity of COE-4 zeolite. It is predicted that the Lewis acid strength increases in the order of Ti-COE-4 < Zr-COE-4 ≤ Sn-COE-4 by the adsorption of different base molecules. Six O-T-O bond angles are divided into different extent to form the analogous trigonal bipyramid structures in the optimized ligand adsorbed complexes. These findings could be beneficial for the structural design and catalytic function modification of the interlayer-expanded zeolites.
    Microporous and Mesoporous Materials 07/2015; 218. DOI:10.1016/j.micromeso.2015.07.020 · 3.45 Impact Factor
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    ABSTRACT: Long-term stability test of Mo/HZSM-5-N catalysts (HZSM-5-N stands for nano-sized HZSM-5) in methane dehydroaromatization (MDA) reaction has been performed with periodic CH4-H2 switch at 1033–1073 K for more than 1000 h. During this test, methane conversion ranges from 13% to 16%, and mean yield to aromatics (i.e. benzene and naphthalene) exceeds 10%. N2-physisorption, XRD, NMR and TPO measurements were performed for the used Mo/HZSM-5 catalysts and coke deposition, and the results revealed that the periodic hydrogenation can effectively suppress coke deposition by removing the inert aromatic-type coke, thus ensuring Mo/HZSM-5 partly maintained its activity even in the presence of large amount of coke deposition. The effect of zeolite particle size on the catalytic activity was also explored, and the results showed that the nano-sized zeolite with low diffusion resistance performed better. It is recognized that the size effect was enhanced by reaction time, and it became more remarkable in a long-term MDA reaction even at a low space velocity.
    Journal of Energy Chemistry 05/2015; 24(3). DOI:10.1016/S2095-4956(15)60309-6 · 2.35 Impact Factor
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    ABSTRACT: Nickel carbide and graphene overlayers were grown on Ni(111), which were in-situ monitored by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) and low energy electron microscopy. CO adsorption and desorption on the formed carbon-modified Ni(111) surfaces were further investigated by NAP-XPS. We found that the carbidic carbon weakens CO adsorption on Ni, resulting in quick CO desorption around room temperature. A full graphene layer on Ni(111) blocks CO adsorption in 10-6 Torr CO while CO intercalates the graphene overlayers in 0.1 Torr CO at room temperature. The major part of intercalated CO molecules desorb extensively around 90 oC from the graphene/Ni interface and the left part get trapped under the graphene. These results suggest that the surface reactivity of a metal catalyst can be strongly modulated by surface carbon structures.
    The Journal of Physical Chemistry C 05/2015; 119(24):150526191240006. DOI:10.1021/acs.jpcc.5b01395 · 4.77 Impact Factor
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    Fan Yang · Dehui Deng · Xiulian Pan · Qiang Fu · Xinhe Bao ·
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    ABSTRACT: Catalysis, as a key and enabling technology, plays an increasingly important role in fields ranging from energy, environment and agriculture to health care. Rational design and synthesis of highly efficient catalysts has become the ultimate goal of catalysis research. Thanks to the rapid development of nanoscience and nanotechnology, and in particular a theoretical understanding of the tuning of electronic structure in nanoscale systems, this element of design is becoming possible via precise control of nanoparticles’ composition, morphology, structure and electronic states. At the same time, it is important to develop tools for in-situ characterization of nanocatalysts under realistic reaction conditions, and for monitoring the dynamics of catalysis with high spatial, temporal and energy resolution. In this review, we discuss confinement effects in nanocatalysis, a concept that our group has put forward and developed over several years. Taking the confined catalytic systems of carbon nanotubes (CNTs), metal-confined nano-oxides, and two-dimensional (2D) layered nano-catalysts as examples, we summarize and analyze the fundamental concepts, the research methods and some of the key scientific issues involved in nanocatalysis. Moreover, we present a perspective on the challenges and opportunities in future research on nanocatalysis from the aspects of: 1) controlled synthesis of nano-catalysts and rational design of catalytically active centers; 2) in-situ characterization of nanocatalysts and dynamics of catalytic processes; 3) computational chemistry with a complexity approximating that of experiments; and 4) scale-up and commercialization of nanocatalysts.
    05/2015; 2(2). DOI:10.1093/nsr/nwv024
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    ABSTRACT: A series of phosphates is investigated as additives to improve the stability of the electrolyte for vanadium flow battery (VFB). Two selected additives show positive effect on the stability of electrolytes under ex-situ stability tests and in situ flow cell experiments. The effects of additives on electrolyte are studied by Nuclear magnetic resonance (NMR), X-ray diffraction (XRD), Raman spectroscopy, Cyclic voltammetry (CV), Electrochemical impedance spectroscopy (EIS) and charge–discharge test. The results show that a VFB using the electrolyte with NH4H2PO4additive demonstrates significantly improved redox reaction reversibility and activity, and higher energy efficiency. In addition, the cell employing the electrolyte with NH4H2PO4 exhibits a charge capacity fading rate much slower than the cell without additives during the cycling at high temperature. These results indicate that the phosphate additives are highly beneficial to improving the stability and reliability of VFB.
    Electrochimica Acta 05/2015; 164. DOI:10.1016/j.electacta.2015.02.187 · 4.50 Impact Factor
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    ABSTRACT: Silica-supported catalysts for the conversion of ethanol to 1,3-butadiene were investigated. The combination of Hf(IV) and Zn(II) resulted in a stable, active, and selective catalyst in which the Zn(II) effectively suppressed the dehydration activity of Hf(IV); the catalyst preparation method plays a crucial role. Using the crystalline Zn-silicate hemimorphite as an alternative Zn(II) source proved to be even more successful in suppressing ethanol dehydration.Keywords: 1,3-butadiene; ethanol; zinc silicate; hemimorphite; heterogeneous catalysis; silica impregnation
    ACS Catalysis 04/2015; 5(6):150424100944007. DOI:10.1021/acscatal.5b00376 · 9.31 Impact Factor
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    ABSTRACT: In heterogeneous catalysis molecule-metal interaction is often modulated through structural modifications at the surface or under the surface of the metal catalyst. Here, we suggest an alternative way towards this modulation by placing a two-dimensional (2D) cover on the metal surface. As an illustration, CO adsorption on Pt(111) surface has been studied under 2D hexagonal boron nitride (h-BN) overlayer. Dynamic imaging data from surface electron microscopy and in-situ surface spectroscopic results under near ambient pressure conditions confirm that CO molecules readily intercalate monolayer h-BN sheets on Pt(111) in CO atmosphere but desorb from the h-BN/Pt(111) interface even around room temperature in ultrahigh vacuum. The interaction of CO with Pt has been strongly weakened due to the confinement effect of the h-BN cover, and consequently CO oxidation at the h-BN/Pt(111) interface was enhanced thanks to the alleviated CO poisoning effect.
    Nano Letters 04/2015; 15(5). DOI:10.1021/acs.nanolett.5b01205 · 13.59 Impact Factor
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    ABSTRACT: Supported VOx/TiO2-Rod catalysts were studied by 51V MAS NMR at high field using a sample spinning rate of 55 kHz. The superior spectral resolution allows for the observation of at least five vanadate species. The assignment of these vanadate species was carried out by quantum chemical calculations of 51V NMR chemical shifts of model V-Surface structures. Methanol oxidative dehydrogenation (ODH) was used to establish a correlation between catalytic activity and the various surface V-Sites. It is found that monomeric V-Species are predominant at low vanadium loadings with two 51V NMR peaks observed at about -502 and -529 ppm. V-Dimers with two bridged oxygens result in a peak at about -555 ppm. Vanadate dimers and polyvanadates connected by one bridged oxygen atom between two adjacent V atoms resonate at about -630 ppm. A positive correlation is found between the V-Dimers giving rise to the -555 ppm peak and the ODH rate, and an even better correlation is obtained by including V-monomer contributions. This result suggests that surface V-Dimers related to the -555 ppm peak and monomers are the primary active sites for the methanol ODH reaction. Furthermore, a portion of the V-Species is found to be invisible to NMR and the level of such invisibility increases with decreasing V-Loading levels, suggesting the existence of paramagnetic V-Species at the surface. These paramagnetic V-Species are also fund to be much less active in methanol ODH.
    ACS Catalysis 04/2015; 5(7):150415154110003. DOI:10.1021/acscatal.5b00286 · 9.31 Impact Factor
  • Peng Jiang · Xinhe Bao · Miquel Salmeron ·
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    ABSTRACT: Heterogeneous catalysis is of great importance for modern society. About 80% of the chemicals are produced by catalytic reactions. Green energy production and utilization as well as environmental protection also need efficient catalysts. Understanding the reaction mechanisms is crucial to improve the existing catalysts and develop new ones with better activity, selectivity, and stability. Three components are involved in one catalytic reaction: reactant, product, and catalyst. The catalytic reaction process consists of a series of elementary steps: adsorption, diffusion, reaction, and desorption. During reaction, the catalyst surface can change at the atomic level, with roughening, sintering, and segregation processes occurring dynamically in response to the reaction conditions. Therefore, it is imperative to obtain atomic-scale information for understanding catalytic reactions.
    Accounts of Chemical Research 04/2015; 48(5). DOI:10.1021/acs.accounts.5b00017 · 22.32 Impact Factor

Publication Stats

11k Citations
2,125.39 Total Impact Points


  • 2015
    • Xiamen University
      Amoy, Fujian, China
  • 1998-2015
    • Dalian Institute of Chemical Physics
      Lü-ta-shih, Liaoning, China
  • 2013
    • Peking University
      • College of Chemistry and Molecular Engineering
      Peping, Beijing, China
  • 1998-2013
    • Chinese Academy of Sciences
      • • State Key Laboratory of Catalysis
      • • Dalian Institute of Chemical Physics
      Peping, Beijing, China
  • 2008-2011
    • State Key Laboratory of Medical Genetics of China
      Ch’ang-sha-shih, Hunan, China
  • 2010
    • Northeast Normal University
      Hsin-ching, Jilin Sheng, China
  • 2001-2005
    • Dalian University of Technology
      • School of Chemical Engineering
      Lü-ta-shih, Liaoning, China
  • 2002
    • University of Science and Technology of China
      • Department of Chemical Physics
      Luchow, Anhui Sheng, China
  • 1992-1997
    • Fritz Haber Institute of the Max Planck Society
      • Department of Inorganic Chemistry
      Berlín, Berlin, Germany
  • 1993-1996
    • Max Planck Society
      München, Bavaria, Germany