Bin Zhang

Catalysis, Green Chemistry, Nanotechnology

PhD
24.97

Publications

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    Preview · Article · Dec 2015
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    ABSTRACT: Highly dispersed, uniform Ni nanoparticles with controlled loadings supported on multi-walled carbon nanotubes (CNTs) were synthesized by atomic layer deposition for hydrogen generation from the hydrolysis of ammonia borane (AB). The catalytic performance of Ni/CNT nanocatalysts prepared with varying ALD cycle numbers was investigated for the hydrolysis of AB in water. The results show that all the Ni/CNT nanocatalysts exhibit excellent catalytic activities towards the hydrolysis of AB, and the Ni/CNTs produced with 200 ALD cycles have the highest hydrogen generation rate, with a total turnover frequency value as high as 26.2 molH2 molNi−1 min−1, which is higher than that of most nickel-based catalysts previously reported in the literature. The hydrolysis completion time and activation energy of AB hydrolysis are 4.5 min and 32.3 kJ mol−1, respectively. Furthermore, 2 ALD cycles of Pt doping (only 0.68 wt%) can significantly improve the catalytic activity and reusability of Ni/CNT nanocatalysts due to its promotion effect. Our results suggest that ALD is a promising technique for designing and fabricating efficient, economical, and non-noble metal nanocatalysts for the hydrolysis of AB.
    No preview · Article · Nov 2015 · Catalysis Science & Technology
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    ABSTRACT: In this study, alternate nonmagnetic Al2O3 and magnetic Fe3O4 multilayer nanofilms with precisely controlled thickness were deposited on carbon nanocoils by atomic layer deposition. The as-synthesized composites exhibit superior microwave absorption performance, which can be flexibly tuned by varying the thickness of each individual layer or the number of layers. The excellent absorption performance arises from the effective impedance matching, alternate multilayer nanostructure and chiral morphology of the samples, and efficient magnetic loss from magnetic constituents. Our work demonstrates a new strategy to tune microwave absorption performance and this method can be extended to exploit other excellent microwave absorbers with alternate multilayer hetero-nanostructures owing to the convenient control of electromagnetic parameters.
    Full-text · Article · Nov 2015 · Carbon
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    ABSTRACT: This paper describes a molecular layer deposition (MLD)-assisted route for the preparation of Cu-ZnO catalysts used in the hydrogenation of levulinic acid to produce γ-valerolactone. A Cu precursor supported on multiwalled carbon nanotubes was coated with Zn-polyurea organic–inorganic hybrid films via MLD first, and the catalyst was obtained after calcination and reduction under mild conditions. The produced catalysts exhibited remarkably enhanced selectivity, efficiency, and stability due to the created Cu-ZnO interface sites (Cu0Zn) and the cooperative effect between Cu0Zn and Cu+. The ratio of Cu0Zn sites could be simply modified by changing the MLD cycle number. The correlation between catalytic activity and the ratio of different Cu species (Cu0Zn, Cu0, and Cu+) suggests that Cu0Zn is the main active site and responsible for the remarkably enhancing catalytic activity and low apparent activation energy.
    Full-text · Article · Aug 2015 · ACS Catalysis
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    ABSTRACT: Iron phosphide (FeP) was introduced to silicon nanowires (SiNWs) via precursor loading and phosphorization. The resultant SiNWs/FeP shows remarkably enhanced photoelectrochemical hydrogen production in comparison with bare SiNWs. The solar power conversion efficiency of SiNWs/FeP is as high as 2.64%, which is 94% of that of SiNWs modified with Pt particles, and is larger than those of silicon-based photocathodes loaded with other non-precious electrocatalysts such as transition metal and their chalcogenides. The faster reaction rate of the hydrogen evolution reaction (HER) on the surface of the SiNWs/FeP than that of the bare SiNWs was confirmed by electrochemistry impedance experiment (EIS). The investigation over the EIS spectra and the flat band potential shows that the onset potential of cathodic photocurrent is mainly influenced by the reaction rate of the HER on the surface of photocathode. The transient photocurrent experiments also suggest the fast kinetics of the HER on the surface of the SiNWs/FeP in comparison with that of the bare SiNWs. This result demonstrates a convenient approach to SiNWs loaded with highly effective electrocatalyst and its promising application potential in photoelectrochemical hydrogen generation.
    Full-text · Article · Jul 2015
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    ABSTRACT: To design highly efficient catalysts, new concepts for optimizing the metal-support interactions are desirable. Here we introduce a facile and general template approach assisted by atomic layer deposition (ALD), to fabricate a multiply confined Ni-based nanocatalyst. The Ni nanoparticles are not only confined in Al2 O3 nanotubes, but also embedded in the cavities of Al2 O3 interior wall. The cavities create more Ni-Al2 O3 interfacial sites, which facilitate hydrogenation reactions. The nanotubes inhibit the leaching and detachment of Ni nanoparticles. Compared with the Ni-based catalyst supported on the outer surface of Al2 O3 nanotubes, the multiply confined catalyst shows a striking improvement of catalytic activity and stability in hydrogenation reactions. Our ALD-assisted template method is general and can be extended for other multiply confined nanoreactors, which may have potential applications in many heterogeneous reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
    Full-text · Article · Jul 2015 · Angewandte Chemie International Edition
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    ABSTRACT: Highly dispersed Pt sub-nanoparticles supported on carbon nanotubes (CNTs) with well controlled size have been prepared by atomic layer deposition. Their particle size distribution was characterized by TEM. The obtained Pt sub-nanoparticles exhibit unusual catalytic performance for styrene hydrogenation. It is revealed that the turnover frequency (TOF) of the Pt/CNTs catalysts for this reaction is well correlated with the Pt particle size. The highest TOF was obtained with a Pt/CNTs catalyst having an average Pt particle size around 0.5-0.7 nm.
    Full-text · Article · Jun 2015 · Catalysis Science & Technology
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    ABSTRACT: Abstract In this study, we demonstrate a flexible method for functionalizing multiwalled carbon nanotubes (MWCNTs) with polyurea (PU) coatings using molecular layer deposition (MLD). Uniform and conformal PU films can be deposited on the surface of pristine MWCNTs without any surface treatment. The PU shell thickness and wrapping amount are precisely tunable by changing the number of MLD cycles. The present MLD functionalizing treatment provides better dispersion of the MWCNTs in highly polar solvents such as N,N-dimethylformamide, dimethyl sulfoxide, and 1-methyl-2-pyrrolidinone. Furthermore, the PU layers improve the compatibility between MWCNTs and the polyurethane matrix. Significant increases in tensile strength and modulus are obtained, resulting in greatly enhanced mechanical properties of PU-functionalized MWCNT/polyurethane composites.
    Full-text · Article · Feb 2015 · Carbon
  • Bin Zhang
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    ABSTRACT: Graphene is a 2D carbon atoms in the form of one atom thick nearly transparent sheet, having many potential uses. However, the other graphene like oxides with different fold types are not easily prepared. The Atomic layer deposition (ALD) is a versatile coating technique, which is able to meet the needs for atomic layer control and conformal films using sequential, self-limiting surface reactions. Here, the graphene-like and folded graphene-like Al2O3 supported Rh catalysts were prepared by ALD modified methods. If the 1-5nm Al2O3 film was deposited on the carbon nanocoils (CNCs) supported Rh catalyst, the graphene like Al2O3 film supported Rh with a 1.5 nm diameter was obtained after roasting in air at 550 oC. In comparison, after rosting the sample that Rh precour was supported on the ALD Al2O3 film coated CNCs, the penciled folded graphene-like Al2O3 film supported Rh with similar diameter was obtained. In the hydrogenation of styrene to ethylbenzene at 30 oC, the TON of folded graphene-like Al2O3 film supported Rh was 100 times than the graphene-like Al2O3 supported Rh catalyst. That may due the folded graphene-like Al2O3 film generates more interaction between the Rh nanoparticles and the surface, which provides more overflow hydrogen.
    No preview · Conference Paper · Oct 2014
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    ABSTRACT: An efficient and selective synthesis of unsymmetrical tetrahydrofurfuryl carbonate and other organic carbonates was realized in the liquid phase transesterification dimethyl carbonate (DMC) with alcohols over the K2CO3/ZrO2 catalyst. Compared with MgO, CaO, MgAl-HDT, ZrO2, and CsF/α-Al2O3, the K2CO3/ZrO2 catalyst with lower basicity displayed a significantly higher activity. The results of FT-IR, XPS and CO2-TPD suggested that the carboxylate species on the surface of the K2CO3/ZrO2 catalyst were the active sites for the DMC transesterification. Other K2CO3 supported TiO2, SiO2 and Al2O3 catalysts showed a rather low catalytic activity due to the lack of carboxylate species.
    Full-text · Article · Jun 2014 · Applied Catalysis B Environmental
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    Bin Zhang · Yulei Zhu · Guoqiang Ding · Hongyan Zheng · Yongwang Li
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    ABSTRACT: The aqueous-phase hydrogenolysis of furfuryl alcohol (FFA) to 1,2-pentanediol (1,2-PeD) was carried out on a series of supported Ru catalysts and MnOx supported Pt, Pd and Rh catalysts. The Ru/MnOx catalysts showed high selectivity for 1,2-PeD, while the Pd and Rh catalysts displayed high selectivity for tetrahydrofurfuryl alcohol. The function of MnOx, the effects of solvent, temperature, H2 pressure and reaction time were further investigated. The support MnOx in the Ru/MnOx catalysts not only suppressed the polymerization of the FFA, but also enhanced the 1,2-PeD selectivity. Low pressure and high temperature favoured the generation of 1,2-PeD, and water significantly enhanced the reaction rate. At 150 °C, 1.5 MPa, the yield of 1,2-PeD was up to 42.1% over the Ru/MnOx catalyst. The proposed mechanism for FFA hydrogenolysis in aqueous medium over the Ru/MnOx catalyst is suggested to occur via a partially hydrogenated intermediate.
    Full-text · Article · Dec 2012 · Green Chemistry
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    ABSTRACT: The promotion effects of alkaline earth metals (Mg, Ca, Sr, Ba) on the catalytic property of the Cu/SiO2 catalyst for the gas phase dehydrogenation of 1,4-butanediol were investigated. The addition of Ca, Sr or Ba to the Cu/SiO2 catalyst resulted in the improvements of the catalytic activity and the gamma-butyrolactone selectivity, and the Cu-Ba/SiO2 catalyst gave 99.6% yield of gamma-butyrolactone even after 900 h running. The catalysts were prepared by co-impregnation and characterized by N-2 physisorption, X-ray diffraction (XRD), SEM, TEM, H-2-temperature programmed reduction (H-2-TPR), N2O-decomposition, ammonia temperature-programmed desorption (NH3-TPD), CO2-TPD, XPS, and FTIR spectroscopy of adsorbed pyridine and CO. On the base of the experimental results, two types of copper species on the reduced catalyst were proposed. The Cu-0 account for the dehydrogenation of 1,4-butanediol, while the electropositive copper species (Cu+) is suggested to be the strong Lewis acid site to catalyze side reactions. The selectivity of gamma-butyrolactone was increased with the increasing of the Cu-0/Cu+ ratio, and the yield of gamma-butyrolactone was increased with copper surface area. The main byproduct 2,3-dihydrofuran may be formed from 1,4-butanediol by the metal/acid-base concerted catalysis.
    Full-text · Article · Nov 2012 · Applied Catalysis A General
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    Lungang Chen · Yulei Zhu · Hongyan Zheng · Chenghua Zhang · Bin Zhang · Yongwang Li
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    ABSTRACT: BACKGROUND: The catalytic degradation of aqueous Fischer–Tropsch (FT) effluents to fuel gas over Ru/AC has been investigated. In order to understand the catalytic performance and stability of oxide-supported Ru catalysts, several oxide supports (titania, zirconia, γ-alumina and silica) were selected for study, with a focus on the hydrothermal stability of catalysts. RESULTS: The catalytic efficiency for transforming the oxygenates in aqueous FT effluents to C1–C6 alkanes decreased in the order: Ru/ZrO2∼ Ru/TiO2 > Ru/SiO2 > Ru/Al2O3. The conversion of alcohols was greatly suppressed over Ru/γ-Al2O3. The former two catalysts (Ru/ZrO2 and Ru/TiO2) exhibited enhanced efficiency and long-term stability (400 h) relative to Ru/SiO2 and Ru/Al2O3. N2-physisorption, XRD and SEM showed that titania and zirconia exhibited high structural stability in an aqueous environment. However, the structures of γ-alumina and silica were unstable due to significant drop in surface area and adverse changes in surface morphology. Especially for the case of the Ru/γ-Al2O3 catalyst, the γ-alumina was transformed into boehmite structure after reaction, and metal leaching and carbon deposition were extensive. CONCLUSION: Ru/ZrO2 or Ru/TiO2 may be a promising alternative for degrading aqueous FT effluents due to their long-term stability. Copyright
    Full-text · Article · Aug 2012 · Journal of Chemical Technology & Biotechnology
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    ABSTRACT: BACKGROUND: Aqueous phase Fischer–Tropsch (FT) effluents co-produced with hydrocarbons in the FT process contain various water-soluble oxygenates, e.g. carboxylic acids, alcohols. Purification of the FT aqueous phase is important from the viewpoint of effective resource utilization and environmental stewardship. In this work, an aqueous-phase hydrodeoxygenation process was investigated for the degradation of FT aqueous phases. RESULTS: The Ru/AC catalyst was determined to be the most active catalyst. The key parameters, i.e. temperature, pressure, weight hourly space velocity and Ru loading, were comprehensively optimized. Under optimal conditions, ca 98% of the oxygenates were converted to C1∼C6 alkanes. The degraded water had no odour, a neutral pH, and as low as 1000 mg L−1 chemical oxygen demand. The Ru/AC catalyst exhibited long-term stability (1300 h) and no ruthenium leaching. A reaction pathway is proposed for this process in which the carboxylic acids are hydrogenated to alcohols via the formation of aldehydes. Alcohols and aldehydes are then converted to methane and alkanes of one carbon atom less than the substrate through CC bond cleavage. CONCLUSIONS: This process is effective for treating FT aqueous phase effluent, and holds great promise for industrial applications due to its high efficiency, simplicity and stability. Copyright
    Full-text · Article · Jan 2012 · Journal of Chemical Technology & Biotechnology
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    Lungang Chen · Yulei Zhu · Hongyan Zheng · Chenghua Zhang · Bin Zhang · Yongwang Li
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    ABSTRACT: For the aqueous-phase hydrodeoxygenation (APHDO) of carboxylic acids over the Ru/C, Ru/ZrO2 and Ru/Al2O3 catalysts, the CO hydrogenation and C–C bond cleavage reactions were studied by collecting reaction kinetics data and the measures of DRIFTS. The C–C bond cleavage was improved at high temperature and with high metal loadings. The acidic supports in combination with Ru metal can favor the CO hydrogenation of carboxyl. The C–C bond cleavage derived from the decarbonylation of acyl on the catalyst was studied by the measures of DRIFTS. The APHDO and DRIFTS results demonstrated that the C–C bond cleavage was favored in the order of Ru/C > Ru/ZrO2 > Ru/Al2O3. The catalysts were characterized by multiple methods (H2-TPR, NH3-TPD, CO-FTIR and DRIFTS of propanoic acid). It is concluded that the effect of support on the reaction routes may be attributed to these factors of catalysts, i.e., surface acidity, metal–support interaction and electronic state of Ru species.
    Full-text · Article · Dec 2011 · Journal of Molecular Catalysis A Chemical
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    ABSTRACT: Hydrogenolysis of glycerol to 1,3-propanediol in aqueous-phase was investigated over Pt-H4SiW12O40/SiO2 bi-functional catalysts with different H4SiW12O40 (HSiW) loading. Among them, Pt-15HSiW/SiO2 showed superior performance due to the good dispersion of Pt and appropriate acidity. It is found that Brønsted acid sites facilitate to produce 1,3-PDO selectively confirmed by Py-IR. The effects of weight hourly space velocity, reaction temperature and hydrogen pressure were also examined. The optimized Pt-HSiW/SiO2 catalyst showed a 31.4% yield of 1,3-propanediol with glycerol conversion of 81.2% at 200 °C and 6 MPa. Graphical Abstract .
    No preview · Article · Feb 2011 · Catalysis Letters

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