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    Chinese Journal of Catalysis
    2014, Vol. 35, No. 2
    Online: 16 January 2014

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    Li and coworkers in their Article on pages 159–167 reported the preparation of copper manganese oxide catalysts doped with transition metal oxides, which could modify the CO adsorption ability of the catalyst and thus affect the catalytic oxidation of CO.

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    Table of Contents
    Table of Contents for VOL.35 No.2
    2014, 35 (2):  0-0. 
    Abstract ( 140 )   PDF (1293KB) ( 652 )  
    Research papers
    The effect of doping transition metal oxides on copper manganese oxides for the catalytic oxidation of CO
    Lina Cai, Zhenhao Hu, Peter Branton, Wencui Li
    2014, 35 (2):  159-167.  DOI: 10.1016/S1872-2067(12)60699-8
    Abstract ( 375 )   [Full Text(HTML)] () PDF (899KB) ( 871 )  

    A series of copper manganese oxides doped with transition metal oxides were prepared by co-precipitation using copper acetate and manganese acetate as precursors, ammonium bicarbonate as precipitant, and metal nitrates as dopants. The catalysts were characterized by N2 adsorption-desorption, X-ray powder diffraction, temperature-programmed reduction, and in situ diffuse reflectance infrared Fourier transform spectroscopy. The results showed that doping transition metal oxides into copper manganese oxides can modify the CO adsorption ability of the catalyst and thus affect the catalytic oxidation of CO.

    Photocatalysis of dinitrotoluene decomposition by H3PW12O40/TiO2 and H4SiW12O40/TiO2 prepared by a modified sol-gel synthesis and solvothermal treatment method
    Changgen Feng, Hairu Shang, Xia Liu
    2014, 35 (2):  168-174.  DOI: 10.1016/S1872-2067(12)60736-0
    Abstract ( 304 )   [Full Text(HTML)] () PDF (757KB) ( 703 )  

    Mesoporous H3PW12O40/TiO2 and H4SiW12O40/TiO2 were synthesized by combining sol-gel technology using a nonionic surfactant P123 as a structure directing agent with solvothermal treatment. X-ray diffraction and Raman spectroscopy results indicated that the TiO2 particles had the anatase phase, and the primary Keggin structures of H3PW12O40 and H4SiW12O40 remained intact after calcination at 400 ℃. N2 adsorption-desorption analysis and scanning electron microscopy showed that the specific surface area and pore volume were increased by the addition of P123. The specific surface area of H3PW12O40/TiO2 and H4SiW12O40/TiO2 increased to 252.2 and 250.0 m2/g, respectively. Ultraviolet-visible absorption spectroscopy showed that compared with pure TiO2, an obvious red shift occurred and the absorption intensity was increased for the composite catalysts. The catalysts were tested and the degradation rate of dinitrotoluene was as high as 95% under the optimum conditions.

    The performance of Pt/ZrxTixAl1-2xO2 as Kerosene cracking catalysts
    Yi Jiao, Jianli Wang, Quan Zhu, Xiangyuan Li, Yaoqiang Chen
    2014, 35 (2):  175-184.  DOI: 10.1016/S1872-2067(12)60732-2
    Abstract ( 278 )   [Full Text(HTML)] () PDF (3556KB) ( 837 )  

    ZrxTixAl1-2xO2 composite oxides for use as supports were prepared by coprecipitation and assessed with regard to their catalytic performance during the kerosene cracking reaction. The catalysts were characterized by N2 adsorption-desorption, scanning electron microscopy-energy dispersive spectrometry, X-ray diffraction, and temperature-programmed desorption (NH3-TPD). The results showed that a support composed of ZrO2:TiO2:Al2O3 in the ratio of 1:1:3 exhibited the highest surface area and pore volume, and had the strongest surface acidity and highest acidic density. Energy dispersive spectroscopy results showed that catalysts from which carbon deposits were removed by heating under oxygen changed very little, and additional experimental data confirmed that these catalysts are readily regenerated while retaining their functionality. The gaseous reaction products produced over ZrO2:TiO2:Al2O3 (1:1:3)-supported Pt catalyst generated during catalytic cracking was 2.1 times and 1.4 times higher than that obtained with thermal cracking at 650 ℃ and 700 ℃, respectively. An examination of the catalytic performance of Pt catalyst supported on composite oxides calcined at 1000 ℃ for 5 h indicated that these materials lost much of their catalytic activity.

    Preparation of MOF(Fe) and its catalytic activity for oxygen reduction reaction in an alkaline electrolyte
    Guoqiang Song, Zhiqing Wang, Liang Wang, Guoru Li, Minjian Huang, Fengxiang Yin
    2014, 35 (2):  185-195.  DOI: 10.1016/S1872-2067(12)60729-3
    Abstract ( 711 )   [Full Text(HTML)] () PDF (807KB) ( 1978 )  

    Effective bifunctional catalysts play a vital role in large-scale commercial applications of rechargeable lithium-air batteries. In this article, a metal-organic framework, MOF(Fe), was prepared by a hydrothermal process using ferric nitrate as the metal ion precursor and trimesic acid as an organic ligand. The structure of the MOF(Fe) was characterized by X-ray diffraction, N2 adsorption-desorption, Transmission electron microscopy, Fourier transform infrared spectroscopy and Thermo-gravimetric analysis. The activity for the oxygen reduction reaction (ORR) and the kinetic behavior of the ORR using the MOF(Fe) were investigated by cyclic voltammetry and rotating disk electrode voltammetry, respectively, using an alkaline electrolyte. The characterization results showed that the MOF(Fe) was highly crystalline with abundant micropores, large specific surface area and high thermal stability. The MOF(Fe) exhibited excellent catalytic activity for the ORR. The ORR mechanism varies with the applied potentials. The ORR occurs through a two-electron pathway at potentials in the range of -0.30 to -0.50 V, but shifts to four-electron pathway with the potentials in the range -0.50 to -0.95 V. In addition, the MOF(Fe) shows excellent catalytic activity for the oxygen evolution reaction (OER) in an alkaline electrolyte. This work opens a new route for the development of effective non-precious metal catalysts based on MOFs for the ORR and OER.

    Nanocrystalline titanium dioxide catalyst for the synthesis of azlactones
    Priyanka Anandgaonker, Ganesh Kulkarni, Suresh Gaikwad, Anjali Rajbhoj
    2014, 35 (2):  196-200.  DOI: 10.1016/S1872-2067(12)60741-4
    Abstract ( 281 )   [Full Text(HTML)] () PDF (8985KB) ( 759 )  

    Titanium dioxide nanoparticles were prepared by a electrochemical reduction method using parameters such as current density, solvent polarity, distance between electrodes, and concentration of stabilizers to control the size of the nanoparticles. The nanoparticles were characterized by UV-Vis spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and their catalytic performance was tested for the synthesis of a series of 4-aryldiene-2-phenyl-5(4)-oxazolones from the cyclodehydration and condensation of the respective aldehyde, hippuric acid and acetic anhydride. Easy availability, reusability and eco-friendliness were some prominent features of the nanocrystalline titanium dioxide catalyst.

    Electrocatalysis of dopamine in the presence of uric acid and folic acid on modified carbon nanotube paste electrode
    Mohammad Mazloum-Ardakani, Mahboobe Abolhasani, Bibi-Fatemeh Mirjalili, Mohammad Ali Sheikh-Mohseni, Afsaneh Dehghani-Firouzabadi, Alireza Khoshroo
    2014, 35 (2):  201-209.  DOI: 10.1016/S1872-2067(12)60734-7
    Abstract ( 298 )   [Full Text(HTML)] () PDF (689KB) ( 718 )  

    A chemically modified carbon paste electrode (CPE), consisting of 2,2'-[(1E)-(1,2-phenylenebis(azanylylidene)] bis(methanylylidene)]bis(benzene-1,4-diol) (PBD) and multiwalled carbon nanotubes (CNTs), was used to study the electrocatalytic oxidation of dopamine using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry (DPV). First, the electrochemical behavior of the modified electrode was investigated in buffer solution. Then the diffusion coefficient, electrocatalytic rate constant, and electron-transfer coefficient for dopamine oxidation at the surface of the PBD-modified CNT paste electrode were determined using electrochemical approaches. It was found that under optimum conditions (pH = 7.0), the oxidation of dopamine at the surface of such an electrode occurred at about 200 mV, lower than that of an unmodified CPE. DPV of dopamine at the modified electrode exhibited two linear dynamic ranges, with a detection limit of 1.0 μmol/L. Finally, DPV was used successfully for the simultaneous determination of dopamine, uric acid, and folic acid at the modified electrode, and detection limits of 1.0, 1.2, and 2.7 μmol/L were obtained for dopamine, uric acid, and folic acid, respectively. This method was also used for the determination of dopamine in a pharmaceutical preparation using the standard addition method.

    Characterization of Pt-TiO2 film used in three formaldehyde photocatalytic degradation systems:UV254 nm, O3+UV254 nm and UV254+185 nm via X-ray photoelectron spectroscopy
    Pingfeng Fu, Pengyi Zhang
    2014, 35 (2):  210-218.  DOI: 10.1016/S1872-2067(12)60740-2
    Abstract ( 353 )   [Full Text(HTML)] () PDF (761KB) ( 616 )  

    Photocatalytic degradation of gaseous formaldehyde for 35 h was performed using Pt-TiO2 film in the following irradiation systems: UV254 nm, O3+UV254 nm, and UV254+185 nm. Concurrent improvements in formaldehyde degradation and O3 removal were achieved by modifying TiO2 with Pt nanoparticles, resulting in a 3.1-3.4-fold O3 elimination increase. X-ray photoelectron spectroscopy (XPS) of the Pt-TiO2 film was carried out to assess the electronic states of the Pt nanoparticles and accumulated organic species. The deconvoluted C 1s and O 1s XPS spectra revealed that the content of carbonyl and carboxyl groups on Pt-TiO2 and degree of catalyst deactivation in the systems studied decreased in the following order: UV254 nm > O3+UV254 nm > UV254+185 nm. Metallic Pt0 was oxidized to a mixture of PtOads and Pt4+ species under O3+UV254 nm and UV254+185 nm irradiation owing to the presence of O3 and hydroxyl radicals, but remained stable under UV254 nm irradiation. Pt species at higher oxidation states can act as electron trapping centers, and improve the photocatalytic activity of Pt-TiO2 and provide reactive sites for O3 decomposition under UV irradiation, resulting in a faster O3 removal rate than that displayed by TiO2. The XPS studies provided valuable information to elucidate the beneficial role of Pt species and the reduction of catalyst deactivation under UV254+185 nm irradiation.

    Screen-printed Pt counter electrodes exhibiting high catalytic activity
    Chunyu Zhao, Yantao Shi, Zhiyong Zhong, Tingli Ma
    2014, 35 (2):  219-226.  DOI: 10.1016/S1872-2067(12)60737-2
    Abstract ( 252 )   [Full Text(HTML)] () PDF (709KB) ( 460 )  

    Counter electrodes (CEs) for dye-sensitized solar cells (DSCs) are important for collecting electrons and catalyzing the iodide/tri-iodide reaction. Pt CEs are commonly prepared by magnetron sputtering, which is expensive and requires vacuum conditions. Incorporating the low cost surfactant Span-85 improved the adhesion between the Pt particles and conductive substrate, and allowed Pt-based CEs to be screen-printed. The screen-printed CE was compared with those prepared by dip-coating and spin-coating. Photoelectric conversion efficiencies of 7.30%, 6.96% and 7.03% were achieved for DSCs containing screen-printed, dip-coated and spin-coated CEs, respectively. Optical transmittance measurements, scanning electron microscopy, and film adhesion tests results showed that the surfactant improved film adhesion and increased transmittance, and the screen-printed CEs exhibited comparable transmittance to the dip-coated CEs. Screen-printing resulted in Pt particles being more uniformly distributed on the substrate, when compared with dip-coating or spin-coating. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel-polarization curves showed that the catalytic activity of the screen-printed Pt-based CEs were higher than that of the other CEs. Screen-printing is suitable for realizing the low-cost large-scale production of large Pt-based CEs.

    Rh-ImiFerroPhos complexes catalyzed asymmetric hydrogenation of β-substituted α,β-unsaturated phosphonates
    Zhengchao Duan, Lianzhi Wang, Xiaoyu Zuo, Xiangping Hu, Zhuo Zheng
    2014, 35 (2):  227-231.  DOI: 10.1016/S1872-2067(12)60742-6
    Abstract ( 387 )   [Full Text(HTML)] () PDF (481KB) ( 477 )  

    A series of chiral ferrocenyl diphosphine ligands (ImiFerroPhos ligands) has been applied to the hydrogenation of β-substituted α,β-unsaturated phosphonates to generate a range of optically active β-substituted alkylphosphonates in good yields with good enantioselectivity (up to 92% ee) under mild reaction conditions.

    NaOH modified WO3/SiO2 catalysts for propylene production from 2-butene and ethylene metathesis
    Surasa Maksasithorn, Damien P. Debecker, Piyasan Praserthdam, Joongjai Panpranot, Kongkiat Suriye, Sirachaya Kunjara Na Ayudhya
    2014, 35 (2):  232-241.  DOI: 10.1016/S1872-2067(12)60760-8
    Abstract ( 355 )   [Full Text(HTML)] () PDF (556KB) ( 765 )  

    A WO3/SiO2 catalyst is used in industry to produce propylene from 2-butene and ethylene metathesis. Catalysts with various WO3 loading (4% to 10%) were prepared by impregnation and tested for the metathesis of ethene and trans-2-butene. Ion exchange of NaOH onto the WO3/SiO2 catalyst was used to mitigate the acidity of the catalysts in a controlled way. At low WO3 loading, the treatment with large amounts of NaOH resulted in a significant decrease in metathesis activity concomitant with significant W leaching and marked structural changes (XRD, Raman). At higher WO3 loading (6% to 10%), the treatment with NaOH mainly resulted in a decrease in acidity. FT-IR experiments after adsorption of pyridine showed that the Lewis acidic sites were poisoned by sodium. Nevertheless, the metathesis activity remained constant after the NaOH treatment. This suggested that the remaining acidity on the catalyst was enough to ensure the efficient formation of the carbene active sites. Interestingly, Na poisoning resulted in some modification of the selectivity. The mitigation of acidity was shown to favor propene selectivity over the formation of isomerization products (cis-2-butene, 1-butene, etc.). Moreover, treatment with NaOH led to a shorter induction period and reduced coke formation on the WO3/SiO2 catalyst.

    Silica-bonded propylpiperazine-N-sulfamic acid as recyclable solid acid catalyst for preparation of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives
    Fahime Khorami, Hamid Reza Shaterian
    2014, 35 (2):  242-246.  DOI: 10.1016/S1872-2067(12)60761-X
    Abstract ( 402 )   [Full Text(HTML)] () PDF (404KB) ( 796 )  

    An efficient method for the synthesis of 2-amino-3-cyano-4-aryl-5,10-dioxo-5,10-dihydro-4H-benzo[g]chromenes and hydroxy-substituted naphthalene-1,4-dione derivatives, using silica-bonded propylpiperazine-N-sulfamic acid as a solid acid, green, heterogeneous catalyst, under ambient and solvent-free conditions, is described. A simple procedure, high yields, short reaction time, safety, and reusability of the catalyst are advantages of these protocols.

    Electrocatalytic measurement of H2O2 concentration using bis(N-2-methylphenyl-salicyldenaminato)copper(Ⅱ) spiked in a carbon paste electrode
    Hossein Khoshro, Hamid R. Zare, Rasoul Vafazadeh
    2014, 35 (2):  247-254.  DOI: 10.1016/S1872-2067(12)60753-0
    Abstract ( 254 )   [Full Text(HTML)] () PDF (577KB) ( 505 )  

    The electrochemical behavior of a bis(N-2-methylphenyl-salicyldenaminato)copper(Ⅱ) complex spiked in a carbon paste electrode (BMPSCu-CPE) and its electrocatalytic reduction of H2O2 were examined using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry. Cyclic voltammetry was used to study the redox properties of BMPSCu-CPE at various potential scan rates. The apparent charge transfer rate constant and the transfer coefficient for the electron transfer between BMPSCu and the carbon paste electrode (CPE) were 1.9±0.1 s-1 and 0.43, respectively. BMPSCu-CPE had excellent electrocatalytic activity for H2O2 reduction in 0.1 mol/L phosphate buffer solution (pH 5.0), and it decreased the overpotential by 300 mV as compared to CPE alone. The diffusion coefficient and kinetic parameters such as the heterogeneous catalytic electron transfer rate constant and electron transfer coefficient for the reduction of H2O2 at the BMPSCu-CPE surface were also determined using electrochemical methods. Differential pulse voltammetry showed two linear dynamic ranges of 1.0-10.0 and 10.0-300.0 μmol/L and a detection limit of 0.63 μmol/L H2O2. The BMPSCu-CPE has excellent reproducibility and long term stability, and it was successfully applied for the determination of H2O2 in two pharmaceutical samples: an antiseptic solution and a hair dying cream.

    Low temperature adsorption of CO on modified, vicinal Cu(100) surfaces:A comparative study
    Przemysław Jan Godowski, Jens Onsgaard
    2014, 35 (2):  255-259.  DOI: 10.1016/S1872-2067(12)60747-5
    Abstract ( 181 )   [Full Text(HTML)] () PDF (438KB) ( 493 )  

    The experimental results of the adsorption of CO on clean and potassium-modified vicinal Cu(100) surfaces at 125 K were present. We studied three surfaces under identical experimental conditions. At 125 K, potassium forms disordered structure on vicinals and CO adsorbs only on sites not occupied by K. It was found that a small percent of the CO molecules dissociate on the stepped interfaces. The influence of steps dominates over pre-adsorbed alkali atoms at 125 K.

    Tribromo melamine as novel and versatile catalyst for the formylation and acetylation of alcohols
    Maryam Hajjami, Arash Ghorbani-Choghamarani, Zahra Karamshahi, Masoomeh Norouzi
    2014, 35 (2):  260-263.  DOI: 10.1016/S1872-2067(12)60748-7|
    Abstract ( 279 )   [Full Text(HTML)] () PDF (348KB) ( 558 )  

    Tribromo melamine has been found to be an efficient and green organocatalyst for the acetylation and formylation reactions of alcohols with acetic anhydride and ethyl formate at room temperature and under mild reaction conditions.

    Cyanoethylation of alcohols and amines by cesium-modified zeolite Y
    Sara Zamanian, Ali Nemati Kharat
    2014, 35 (2):  264-269.  DOI: 10.1016/S1872-2067(12)60751-7
    Abstract ( 244 )   [Full Text(HTML)] () PDF (575KB) ( 725 )  

    Zeolite Y modified by cesium and magnesium ions was prepared by ion-exchange and impregnation methods, and its activity in the cyanoethylation of aliphatic and aromatic alcohols and amines was investigated. During the preparation of some samples, the transformation of zeolite Y into a pollucite-type phase occurred. This phase exhibited good activity in the cyanoethylation of aliphatic alcohols. The prepared solids modified by the impregnation method were more active than the ion-exchanged solids. The activities of the catalysts, in contrast to other basic solids, were scarcely affected by the presence of air or moisture. A correlation between catalyst basicity and catalytic activity is discussed. The catalysts were characterized by X-ray diffraction, volumetric nitrogen adsorption surface area measurement, and CO2 temperature-programmed desorption. Scanning electron microscopy revealed that the particles of the modified nanocatalysts were < 40 nm. The reaction of acrylonitrile with linear alcohols in the presence of the catalysts was accelerated by microwave irradiation.

    Effects of Bi and Ni on the properties of a vanadium phosphorus oxide catalyst
    Yun Hin Taufiq-Yap, Choon Seon Yuen, Nawi @ Mohamed Nurul Suziana, Ramli Irmawati
    2014, 35 (2):  270-276.  DOI: 10.1016/S1872-2067(12)60749-9
    Abstract ( 358 )   [Full Text(HTML)] () PDF (576KB) ( 625 )  

    Vanadium phosphorus oxide (VPO) catalysts were synthesized by the dihydrate method which involved the two steps for the preparation of the dihydrate (VOPO4×2H2O) and the precursor hemihydrate (VOHPO4×0.5H2O). Bi and Ni salt were added into the mixture of VOPO4×2H2O and isobutanol, and the obtained precursors were calcined in a flow of a n-butane/air mixture to produce the promoted VPO catalysts. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, inductively coupled plasma-atomic emission spectroscopy, scanning electron microscopy (SEM), and H2 temperature-programmed reduction (H2-TPR). Their catalytic properties were tested using a fixed-bed microreactor. All the catalysts gave main XRD peaks at 2θ = 22.9°, 28.5°, and 30.0°, attributing to the (020), (204), and (221) planes of the pyrophosphate phase (VO)2P2O7, respectively. The promoted catalysts have smaller crystallite size and higher specific surface areas. SEM micrographs revealed the formation of more prominent plate-like crystallites that were arranged as rosette clusters. H2-TPR results showed that the promoted catalysts had lower reduction peak temperatures and possessed higher amounts of V5+-O2- and V4+-O- pairs, which gave higher selectivity and activity in the selective oxidation of n-butane to maleic anhydride.