Tianbo Zhao

Beijing Institute of Technology, Peping, Beijing, China

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Publications (24)54.87 Total impact

  • Jing Li · Tianbo Zhao · Fengyan Li · Baoning Zong · Zexue Du · Jianli Zeng
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    ABSTRACT: Hierarchical porous mullite monoliths have been prepared via a sol–gel process accompanied by phase separation. Propylene oxide (PO) acted as an acid scavenger to mediate the gelation, poly(ethylene oxide) (PEO) as the phase-separation inducer and network former, aluminum chloride hexahydrate (AlCl3·6H2O) as the aluminum source. The route was improved by using hypotoxic tetraethylorthosilicate (TEOS) and nontoxic aqueous colloidal silica (Aq) instead of tetramethoxysilane (TMOS). The synthesis mechanism and microstructural development were comparatively investigated by scanning electron microscopy (SEM), thermogravimetry-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and nitrogen adsorption–desorption. It was found that the mixing degree of precursors and concurrent process of gelation and phase separation are key elements to get well-defined hierarchical porous mullite monoliths. In addition, the monoliths with high relative crystallinity are more likely to be obtained under low transformation temperature in organic silicon sources system.
    No preview · Article · Dec 2015
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    Jian Qi · Quan Jin · Kun Zhao · Tianbo Zhao
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    ABSTRACT: In order to prepare a highly active catalyst for the catalytic cracking of larger molecules, a novel micro-mesoporous silicoaluminophosphate composite (define as mesoporous SAPO-5) with hierarchical tri-modal pore size distributions has been firstly synthesized via post-synthetic method in acidic condition and subsequently characterized. Morphology control of the composite is attempted by adjusting pH value of the synthetic system. Three different morphologies of composite, including sphere-, rod- and net-like, are obtained in the different conditions. Possible mechanism for the formation of mesoporous SAPO-5 has been proposed. The mesoporous SAPO-5 exhibits higher cracking activity than conventional microporous SAPO-5 for cracking of 1, 3, 5-triisopropylbenzene (1, 3, 5-TIPB) under the same reaction conditions. The result indicates that the mesoporous SAPO-5 with hierarchical pore structure is favorable for catalytic cracking of large molecule. When the cumene as the reaction molecule, the microporous SAPO-5 catalyst exhibits higher conversion in catalytic cracking of cumene compared to the mesoporous SAPO-5, and the result may be attributed to that microporous SAPO-5 has much stronger acidity and specific selectivity than mesoporous SAPO-5 catalyst in catalytic cracking of cumene. Meanwhile, corresponding carbenium ion mechanism can account for the products formed during the whole reaction process.
    Full-text · Article · Aug 2015 · Journal of Porous Materials
  • Mingliang Sun · Tianbo Zhao · Jia Wang · Zhaofei Ma · Fengyan Li
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    ABSTRACT: Using cheap n-butylamine as template, ZSM-5 zeolites have been successfully synthesized and coated on monolithic interconnected macroporous Al2O3 by the secondary growth method. The use of cheap n-butylamine could significantly reduce the synthesis cost. Hierarchical monolithic ZSM-5 zeolites were prepared from synthetic mixtures with different H2O/Na2O or SiO2/Al2O3 ratio. The synthesized samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and N2 adsorption-desorption. The results show that the hierarchical monolithic zeolites were obtained with cheap n-butylamine template as template. During the hydrothermal reaction process, the morphology of the micrometer-sized support was well maintained. The irregular crystals were formed in a wide range of the H2O/Na2O or SiO2/Al2O3 ratio of synthetic mixtures and coated on monolithic Al2O3. The relative crystallinity of the zeolites was highest at H2O/Na2O=250 or SiO2/Al2O3=160. This type of composites exhibited hierarchical porous structures and relatively high specific surface areas.
    No preview · Article · Jul 2015 · Chinese Journal of Chemistry
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    ABSTRACT: An efficient and reliable technique to evaluate the degree of coverage of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was described. The method was based on a quantitative analysis of RDX leakage carried out with a high performance of liquid chromatography (HPLC). For this study, replicated analyses were performed on coated samples prepared by different kinds of coating materials and methods. The efficiency of characterization by using both HPLC and scanning electron microscope was compared. To note, the evaluation through former technique is more on macroscopic perspective rather than morphological observation of sample. Meanwhile, the HPLC method also provided characterization results that were in good agreement with morphology observation. A noteworthy advantage of this original technique is that the evaluation of coating quality of melt-cast explosives can be carried out under similar conditions. The experimental data were provided for deep understanding of the soluble behavior of coated RDX and its possible applications in practical problems.
    No preview · Article · Oct 2012 · Chromatographia
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    ABSTRACT: The main objective of this study was to develop an easy method, based on the hydrogen-bonding interaction between a polymer network and a sucrose solution, for fabricating bulk nanostructured carbon materials. In this study, bulk nanostructured carbon materials were synthesized by using the superabsorbent polymers with multiple networks, prepared in advance, as templates and sucrose as a carbon precursor. The synthesis scheme consisted of preparing the multiple polymer networks, saturating it with sucrose solution and carbonizing the sucrose solution. The above procedure leads to the carbon materials with a variety of new morphologies: leaves-like carbon sheets, carbon clusters, carbon sticks and spherical carbons. This synthesis scheme allowed the fabrication of bulk nanostructured carbon materials, and a mechanism for their formation is proposed.
    No preview · Article · Aug 2012 · Materials Chemistry and Physics
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    Shuai Zhang · Tianbo Zhao · Jia Wang · Xiaoling Qu · Wei Chen · Yin Han
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    ABSTRACT: A method for routine determination of fluorine, chlorine and bromine in household products was developed and validated. In this work, halogen analyses were made based on oxygen bomb combustion followed by ion chromatography (IC). The chromatographic analysis was performed by an IonPac AS19 hydroxide-selective anion-exchange column, a reagent free ion chromatograph eluent generator and an anion self-regenerating suppressor in 10 min. The response was linear (r ≥ 0.9995) in the entire investigated domain. The limit of detection for the halogens was in the range of 2 to 9 × 10−3 mg/L and the limit of quantification was lower than 8 mg/Kg with 20 µL of injection volume. The certified reference material of ERM-EC 681k was pretreated using an oxygen bomb combustion procedure to demonstrate the precision of the proposed method. The quantitative analysis results obtained by IC for the target elements were 797 ± 9 mg/Kg chlorine and 786 ± 25 mg/Kg bromine, which were in good agreement with the certified values of 800 ± 4 mg/Kg chlorine, 770 ± 5 mg/Kg bromine for ERM-EC 681k, respectively. This validated method was successfully applied for the analysis of fluorine, chlorine and bromine in household product samples, and the variation of halogen contained among the tested samples was remarkable.
    Preview · Article · Jun 2012 · Journal of chromatographic science
  • Jian Qi · Tianbo Zhao · Xin Xu · Fengyan Li · Guida Sun
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    ABSTRACT: The objective of this work was to evaluate the use of hydrothermal method for the synthesis of small and homogeneous silicalite-1 zeolite. The influences of crystallization time, crystallization temperature, different organic solvents and different TPAOH template concentrations were investigated. The results showed these parameters had played important roles in controlling particle size of silicalite-1 zeolite.
    No preview · Article · Aug 2011 · Journal of Porous Materials
  • Shuai Zhang · Tianbo Zhao · Haiwang Wang · Jia Wang
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    ABSTRACT: Three methods were developed for analysis of benzene, toluene, p-xylene, m-xylene and o-xylene (BTX) in a solid-liquid mixing paint. These methods were based on solid phase extraction-thermal desorption-gas chromatography with a flame ionization detector (SPE-TD-GC-FID), ultra performance liquid chromatography-photodiode array detector (UPLC-PDA) and gas chromatography-mass spectrometry (GC-MS). At their optimum conditions of operation, the developed methods were compared in terms of recovery, sensitivity, selectivity and universality. Although the time required for GC-MS analysis was shorter than for GC-FID and UPLC-PDA, it offered relatively poorer recoveries and suffered from matrix interferences. All of the mentioned methods were proven to be ideal for the analysis of targeted analytes; SPE-TD-GC-FID was particularly fit for the determination of trace level BTX residues present in the complex matrix. As one of the sample pretreatment techniques, the novel SPE also showed some selectivity towards BTX and was found to be superior to the conventional SPE.
    No preview · Article · Jul 2011 · Chromatographia
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    ABSTRACT: An easy method is described for fabricating carbon sheets with nanostructures using sucrose as a carbon precursor and a layered superabsorbent polymer (LSAP) as a structure-directing agent. The method is based on the interaction of the three-dimensional polymer networks of the LSAP with a sucrose solution in the hydrogel cells. The synthesis scheme consists of: (a) preparation of the LSAP, (b) preparation of layered hydrogels by immersing the LSAP in the sucrose solution for 2days, (c) carbonization of the layered hydrogels containing the sucrose solution. The synthesized carbon sheets show different microstructures including petal-like, regular and interleaved types, which can be controlled by simply adjusting the initial concentration of the sucrose solution in the hydrogel cells. Moreover, a formation mechanism for the carbon sheets is proposed.
    No preview · Article · Feb 2011 · Carbon
  • Jian Qi · Tianbo Zhao · Xin Xu · Fengyan Li · Guida Sun
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    ABSTRACT: A novel micro-micro/mesoporous silicoaluminophosphate ZSM-5-SAPO-5/MCM-41 (define as MZS-5) composite material with regular spherical morphology was synthesized through a novel process of the self-assembly of CTAB surfactant micelles with silica-alumina source which originated from the alkaline treatment of ZSM-5 zeolite. The physical properties of the MZS-5 composite material were characterized by XRD, FT-IR, Nitrogen adsorption–desorption, SEM and Py-FTIR techniques. Catalytic tests showed that the MZS-5 composite catalyst exhibited higher catalytic activity compared with the conventional microporous ZSM-5, SAPO-5 zeolite and mesoporous Al-MCM-41 molecular sieve for catalytic cracking of 1,3,5-triisopropylbenzene (TIPB). The remarkable catalytic reactivity of TIPB molecules was mainly attributed to the presence of the hierarchical zeolite structure. In the MZS-5 structure, the mesopores provided pathways for transportation of larger molecules and the microporous ZSM-5 and SAPO-5 zeolite provided acidic sites for catalytic activity. Graphical Abstract A novel micro-micro/mesoporous silicoaluminophosphates MZS-5 catalyst exhibited higher catalytic activity than microporous ZSM-5, SAPO-5 and mesoporous Al-MCM-41 for catalytic cracking of 1,3,5-triisopropylbenzene due to its hierarchical porosity.
    No preview · Article · Feb 2011 · Journal of Porous Materials
  • Jian Qi · TianBo Zhao · Xin Xu · FengYan Li · GuiDa Sun
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    ABSTRACT: A novel micro-mesoporous silicoaluminophosphate (MUS-5) with controlled morphology has been first synthesized in a two-step route. The physical properties of the silicoaluminophosphate were characterized using XRD, SEM, TEM, nitrogen adsorption-desorption and NH3-TPD techniques. When the pH value of the solution system was varied in the range from 2.0 to 5.0, three different morphologies of silicoaluminophosphate including chain-like, flower-like and barrel-like morphology were obtained. Catalytic tests showed that the silicoaluminophosphate exhibited higher catalytic activity compared with the conventional microporous SAPO-5 under the same conditions for catalytic cracking of 1,3,5-triisopropylbenzene heavy aromatics. The remarkable catalytic reactivity was mainly attributed to the presence of the hierarchical porosity in the silicoaluminophosphate catalyst.
    No preview · Article · Nov 2010 · Science China-Chemistry
  • Xin Xu · Tianbo Zhao · Jian Qi · Yuntao Guo · Ce Miao · Fengyan Li · Meng Liang
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    ABSTRACT: Macroporous silica–alumina composites with continuous micrometer-scale pores were synthesized by seed-induced vapor-phase transport treatment. The parent silica–alumina monolith was employed as the silica and alumina source as well as the template for the three-dimensional interconnected structure. The silicalite-1 precursor solution with dispersed zeolite seeds was drawn into the pore channels of the parent monolith for modification by in-situ and layer-by-layer methods before the hydrothermal crystallization, which was believed to play a significant inducing role in the zeolite growing process. The composites synthesized are expected to display high catalytic performance on the bulky molecules since they incorporate the strong acidic advantages of the microporous zeolite and the macroporous pathways of the monolithic skeletons for mass transport.
    No preview · Article · Aug 2010 · Materials Letters
  • Shuai Zhang · Tianbo Zhao · Xin Xu · Haiwang Wang · Ce Miao
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    ABSTRACT: A novel method was developed and validated for determination of benzene, toluene, p-xylene, m-xylene, o-xylene (BTEX) in a solid–liquid mixing matrix. It makes use of solid phase extraction and thermal desorption (SPE-TD), followed by gas chromatographic flame ionization detector analysis (GC-FID). The trapped BTEX can be measured directly after thermal desorption onto the stainless-steel packed chromatographic column. The effect of tailing area of solvent was removed with the use of SPE-TD technique, and the result shows good reproducibility with very little matrix dependency. The study also supports that the lifetime of the Tenax adsorption tube could be extended over 150 desorption operation at 200°C, which enables performing excellent stability and reproducibility of BTEX analysis. KeywordsGas chromatography-Solid phase extraction and thermal desorption-Stainless-steel packed chromatographic column-BTEX in painting materials
    No preview · Article · Jun 2010 · Chromatographia
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    ABSTRACT: Novel hierarchical zeolites with continuous micrometer-scale macropores and mesopores other than popular nanometer-scale mesopores and micropores were synthesized by transforming the skeletons of the silica monolith into zeolites through both the steam-assisted conversion and nanocasting methods. Results showed the novel hierarchical zeolites exhibited high catalytic activity for catalytic cracking large molecules. KeywordsHierarchical zeolites-Catalytic cracking
    No preview · Article · Jun 2010 · Catalysis Letters
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    ABSTRACT: A new type meso-ZSM-5 composite zeolite with interconnected macropores and skeletons under hydrothermal conditions was prepared through zeolite degraded method. The skeletons can be templated to the morphology of network in different conditions. The physical properties of the meso-ZSM-5 composite zeolite were characterized by XRD, IR, SEM and nitrogen sorption techniques. Catalytic tests show that the meso-ZSM-5 composite zeolite catalyst exhibits high catalytic activity compared with the conventional microporous ZSM-5 zeolites for catalytic cracking of 1,3,5-triisopropylbenzene. The high 1,3,5-triisopropylbenzene conversion are mainly assigned to the presence of the hierarchical porosity of the pore walls. The macropores offer easier transport and access to the active sites and the macroporous walls built by ZSM-5 crystals provide the acidic sites for reaction. KeywordsMeso-ZSM-5-Network structure-Cracking-1,3,5-triisopropylbenzene
    No preview · Article · Apr 2010 · Journal of Porous Materials
  • Jian Qi · Tianbo Zhao · Xin Xu · Fengyan Li · Guida Sun · Ce Miao · Haiwang Wang
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    ABSTRACT: A novel mesoporous beta with interconnected macropores and skeletons under hydrothermal conditions was prepared through zeolite degraded method. The skeletons can be templated to the morphology of network in different conditions. The physical properties of the mesoporous beta were characterized by XRD, SEM and nitrogen sorption techniques. Catalytic tests show that the mesoporous beta catalyst exhibits high catalytic activity compared with the conventional microporous beta zeolites for catalytic cracking of 1,3,5-triisopropylbenzene. The high 1,3,5-triisopropylbenzene conversion are mainly assigned to the presence of the hierarchical porosity of the pore walls.
    No preview · Article · Jun 2009 · Catalysis Communications
  • Qian Lei · Tianbo Zhao · Fengyan Li · Yan Fen Wang · Lingling Hou
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    ABSTRACT: Zeolite beta monoliths with hierarchical porosity were prepared by the steam-assisted conversion of pre-seeded bimodal pore silica gel using the Layer-by-Layer process. The bimodal pore silica gel acts as both macrotemplates and silica source. The zeolite beta monoliths were characterized by X-ray diffraction, scanning electron microscopy, IR absorption spectra and nitrogen adsorption measurements. This zeolite beta monolith had hierarchical porosity: the unique micropores within the zeolite, the small macropores generated by aggregation of crystallites and three dimensionally interconnected macropores formed by template of silica gel. It is believed that the hierarchical structured zeolite monoliths will show good properties and potential applications the fields of catalyst, ion exchange, and adsorption.
    No preview · Article · Nov 2008 · Journal of Porous Materials
  • Mingfang Zheng · Tianbo Zhao · Wenguo Xu · Fengyan Li · Yue Wang
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    ABSTRACT: Cu/SiO2 catalyst with bimodal pore structure was prepared by co-gelation reactions of tetramethoxysilane (TMOS) and copper nitrate in the presence of poly (ethylene oxide) (PEO) with an average molecular weight of 10,000 and the catalyst of acetic acid. In this process, the interconnected macroporous morphology was formed when transitional structures of spinodal decomposition were frozen by the sol–gel transition of silica. The addition of copper into the silica–PEO system had a negligible effect on the morphology formation. In gel formation, it was found that the crystallite sizes of the CuO estimated from the peak width in the Cu/SiO2 with the presence of PEO were not small as expected. It was considered that there was no obvious interaction between the Cu cation and PEO, most of the copper ions in wet silica gel were present in the outer solution. They easily aggregated as copper salts in the drying process of wet gel and decomposed into CuO particles in heating. While in the Cu/SiO2 with the absence of PEO, the Cu was selectively entrapped as small particles in the gel skeleton due to the interaction between Cu aqua complex and silica gel network.
    No preview · Article · Jan 2007 · Journal of Materials Science
  • Yangchuan Tong · Tianbo Zhao · Fengyan Li · Yue Wang
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    ABSTRACT: A synthetic method for the fabrication of beta zeolite monolith with hierarchical pore system through transformation of the amorphous walls of the silica monolith using carbon materials as transitional hard template, is described. The silica monolith is immersed in the mixture of sucrose and sulfuric acid solutions and is thermally treated at 160 °C for 6 hours. The composite materials are carbonized under the protection of nitrogen to obtain the carbon-silica composites. The carbon/silica composition is then transferred to an autoclave for further reaction to crystallize zeolite beta after being impregnated with the clear aluminosilicate solution. In the zeolite synthesis process, the original amorphous materials contain Si-O and Al-O bonds, whereas the crystalline zeolite product contains Si-O-Al linkages. Various shapes of as-synthesized beta monolith can be easily obtained, because the silica templates result from sol-gel conversion and can be molded in different shapes.
    No preview · Article · Aug 2006 · Chemistry of Materials
  • Mingfang Zheng · Tianbo Zhao · Wenguo Xu · Fengyan Li · Yue Yang
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    ABSTRACT: CuO/SiO2 and NiO/SiO2 with bimodal pore structure were prepared by sol-gel reactions of Tetra-methoxysilane (TMOS) and the respective metal nitrate in the presence of poly (ethylene oxide) (PEO) with an average molecular weight of 10 000 and the catalyst of acetic acid. In this process, the interconnected macroporous morphology was formed when transitional structures of spinodal decomposition were frozen by the sol-gel transition of silica. The addition of copper and nickel into the silica-PEO system had a negligible effect on the morphology formation. In gel formation, it was found that NiO crystalline sizes in the samples increased with decreasing Si/Ni molar ratio. It was considered that PEO interacted with both silica and nickel cations. In the CuO/SiO2 with the presence of PEO, CuO crystalline sizes were larger than those of NiO/SiO2. It was considered that there was no obvious interaction between the Cu cation and PEO, most of the copper ions in wet silica gel were present in the outer solution. They easily aggregated as copper salts in the drying process of wet gel and decomposed into CuO particles in heating. While in the CuO/SiO2 with the absence of PEO, the Cu was selectively entrapped as small particles in the gel skeleton due to the interaction between Cu aqua complex and silica gel network.
    No preview · Article · Aug 2006 · Journal of Sol-Gel Science and Technology

Publication Stats

203 Citations
54.87 Total Impact Points

Institutions

  • 2008-2015
    • Beijing Institute of Technology
      Peping, Beijing, China
  • 2006
    • Technical Institute of Physics and Chemistry
      Peping, Beijing, China
  • 2005
    • Beijing Institute of Petrochemical Technology
      Peping, Beijing, China