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Chinese Journal of Catalysis
2012, Vol. 33, No. 8
Online: 01 August 2012


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Qiao and coworkers in their article on pages 1266–1275 report that Ni/ZnO effectively catalyzes aqueous-phase reforming and hydrogenolysis of glycerol to 1,2-propanediol without added H₂. The catalyst with the highest Ni dispersion showed a superior catalytic performance to precious metal catalysts.

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Table of Contents for Vol. 33 No. 8 2012, 33 (8):  0-0.  Abstract ( 1133 )   PDF (1901KB) ( 894 )

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Recent Progress of Cu-Based Catalysts for Catalytic Elimination of CO YU Qiang, GAO Fei, DONG Lin 2012, 33 (8):  1245-1256.  DOI: 10.3724/SP.J.1088.2012.20401 Abstract ( 3322 )   [Full Text(HTML)] () PDF (577KB) ( 1287 )   Catalytic elimination of CO mainly includes complete oxidation (CO-COOX) and preferential oxidation of CO (CO-PROX). First, combined with our group’s research, a brief introduction to the active species and the interaction between components in Cu-based catalysts for CO-COOX was presented from the perspective of the catalyst system. Then recent progress in CO-PROX under H2-rich over Cu-based catalysts was systematically summarized. Influence of the preparation method, promoter, and support of CuO-CeO2 catalyst as well as transition metal ions doped support (CuO/Ce1-xMxO2), and inverse structure (CeO2/CuO) on the catalytic performance in CO-PROX was elaborated. Finally, the application problems and future research trend of Cu-based catalysts for catalytic removal of CO were discussed and summarized.

Research Briefing

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Mesoporous WO3 Supported Pt Catalyst for Hydrogenolysis of Glycerol to 1,3-Propanediol LIU Long-Jie, ZHANG Yan-Hua, WANG Ai-Qin, ZHANG Tao 2012, 33 (8):  1257-1261.  DOI: 10.1016/S1872-2067(11)60425-7 Abstract ( 3353 )   [Full Text(HTML)] () PDF (366KB) ( 1201 )   Mesoporous tungsten trioxide (m-WO3) was prepared using an evaporation-induced self-assembly method and was used as the support of Pt for hydrogenolysis of glycerol to produce 1,3-propanediol. In comparison with commercial WO3, the m-WO3 presents a much larger surface area and better reduciblity, which make the Pt particles highly dispersed on the support. At a reaction condition of 180 oC, 5.5 MPa H2, and reaction time of 12 h, the Pt/m-WO3 catalyst afforded 18.0% conversion of glycerol and 39.2% selectivity for 1,3-propanediol, both of which are much higher than those on commercial Pt/WO3 catalyst.

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A Facile Synthesis of 3,4-Dialkoxythiophenes through Decarboxylation Catalyzed by Metal Phthalocyanines ZHAO Jun-Long, GOU Xiao-Feng, HUA Cheng-Wen, WANG Lan-Ying 2012, 33 (8):  1262-1265.  DOI: 10.1016/S1872-2067(11)60419-1 Abstract ( 2391 )   [Full Text(HTML)] () PDF (407KB) ( 900 )   3,4-Dialkoxythiophenes are electron rich and their polymers have a narrow energy gap, so they have recently attracted considerable attention in the field of organic semiconducting materials. However, the traditional synthetic approach suffers from some drawbacks, so the development of efficient methods for the synthesis of 3,4-dialkoxythiophenes is needed. A novel, efficient decarboxylation of 2,5-dicarboxy-3,4-dialkoxythiophenes was achieved in excellent yields (up to 95%) and purities using metal phthalocyanines in water, which avoids the use of organic polar solvents, and the recovered catalyst was successfully used in subsequent reactions. Furthermore, the desired products, 3,4-dialkoxythiophenes, were conveniently separated by steam distillation. This method has several advantages such as environmental friendliness, ease of manipulation, and a short reaction time. This environmentally friendly procedure represents a promising green route for the decarboxylation of these important compounds.

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Reforming and Hydrogenolysis of Glycerol over Ni/ZnO Catalysts Prepared by Different Methods HU Ji-Ye, LIU Xiao-Yu, WANG Bin, PEI Yan, QIAO Ming-Hua, FAN Kang-Nian 2012, 33 (8):  1266-1275.  DOI: 10.1016/S1872-2067(11)60405-1 Abstract ( 3058 )   [Full Text(HTML)] () PDF (658KB) ( 1696 )   The catalytic conversion of glycerol to 1,2-propanediol (1,2-PDO) is generally conducted batch-wise in an autoclave in the presence of high pressure H2. The reforming and hydrogenolysis of glycerol to 1,2-PDO over Ni/ZnO catalysts in a continuous flow fixed-bed reactor without added H2 was reported. The Ni/ZnO catalysts were prepared by wetness impregnation (WI), co-precipitation (CP), hydrothermal treatment (HT), and carbon microsphere hard-templating (CT) methods. The catalysts were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), transmission electron microscopy (TEM), and H2 titration. At a low weight hourly space velocity (WHSV) of glycerol, the 1,2-PDO produced got degraded to ethanol and gas phase products over catalysts with high Ni dispersion, while at a high WHSV, the selectivity for 1,2-PDO was limited by the hydrogenation of the acetol intermediate. At the optimized WHSV, the catalyst with a higher Ni dispersion was more selective for 1,2-PDO, and over the Ni/ZnO catalyst with the highest Ni dispersion, the highest selectivity of 54.9% for 1,2-PDO was obtained at a glycerol conversion of 85.4% at the WHSV of 0.84 h–1.

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Enhanced Sonocatalytic Degradation of Rhodamine B by Graphene-TiO2 Composites Synthesized by an Ultrasonic-Assisted Method ZHU Lei, Trisha GHOSH, Chong-Yeon PARK, MENG Ze-Da, OH Won-Chun 2012, 33 (8):  1276-1283.  DOI: 10.1016/S1872-2067(11)60430-0 Abstract ( 2562 )   [Full Text(HTML)] () PDF (637KB) ( 1699 )   A series of graphene-TiO2 composites was fabricated from graphene oxide and titanium n-butoxide (TNB) by an ultrasonic-assisted method. The structure and composition of the nanocomposites were characterized by Raman spectroscopy, BET surface area measurements, X-ray diffraction, transmission electron microscopy, and ultraviolet-visible absorption spectroscopy. The average size of the TiO2 nanoparticles on the graphene nanosheets was controlled at around 10–15 nm without using surfactant, which is attributed to the pyrolysis and condensation of dissolved TNB into TiO2 by ultrasonic irradiation. The catalytic activity of the composites under ultrasonic irradiation was determined using a rhodamine B (RhB) solution. The graphene-TiO2 composites possessed a high specific surface area, which increased the decolorization rate for RhB solution. This is because the graphene and TiO2 nanoparticles in the composites interact strongly, which enhances the photoelectric conversion of TiO2 by reducing the recombination of photogenerated electron-hole pairs.

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Catalytic Performance of Layered Double Hydroxides Co-Mn-Al for Ozonation of Organic Pollutants in Water SUI Ming-Hao, DUAN Biao-Biao, SHENG Li, HUANG Shu-Hang, SHE Lei 2012, 33 (8):  1284-1289.  DOI: 10.1016/S1872-2067(11)60392-6 Abstract ( 2833 )   [Full Text(HTML)] () PDF (523KB) ( 959 )   The catalytic activity of layered double hydroxides containing Co, Mn, and Al for the ozonation of organic pollutants in water was investigated. The Co-Mn-Al layered double hydroxides were prepared by coprecipitation. Nitrobenzene was used as a model compound, and it was shown that the degradation and mineralization of nitrobenzene was increased by the presence of Co-Mn-Al layered double hydroxides as compared to ozonation alone. Both an indirect method of adding a scavenger (tert-butanol) of the hydroxyl radical chain reaction and direct electron spin resonance using 5,5-dimethyl-1-pyrroline-N-oxide as a spin trapping agent were used to investigate the generation of hydroxyl radicals in the ozonation by the Co-Mn-Al layered double hydroxides. The inhibiting effect of tert-butanol on the degradation of nitrobenzene and the detection of the stronger 5,5-dimethyl-1-pyrroline-N-oxide/hydroxyl radical adduct showed that the Co-Mn-Al layered double hydroxides catalyzed the generation of hydroxyl radicals.

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Controlling Crystal Transformation between Zeolite ZSM-5 and Mordenite without Organic Structure-Directing Agent HUANG Xian-Liang, ZHANG Rong-Rong, WANG Zheng-Bao 2012, 33 (8):  1290-1298.  DOI: 10.1016/S1872-2067(11)60400-2 Abstract ( 2571 )   [Full Text(HTML)] () PDF (576KB) ( 989 )   Zeolite crystals were synthesized at a lower temperature (150 °C) by adding a nucleation solution prepared at higher temperature (190 °C) to the mother solution. The effects of the Na2O/SiO2 ratio, nucleation time of the nucleation solution, and the ratio of Na2O/SiO2 ratio in the mother solution on crystal transformation between ZSM-5 and mordenite were investigated. The transformation between zeolite ZSM-5 and mordenite could be controlled effectively by changing the overall Na2O/SiO2 ratio in the overall solution. A Na2O/SiO2 ratio of 0.18 formed a boundary between ZSM-5 and mordenite phases when the overall solution had a composition of xNa2O:100SiO2:2.5Al2O3: 12SO42-:4000H2O. When the Na2O/SiO2 ratio was increased higher than 0.18 by altering the composition of the mother solution, the ZSM-5 product formed by nucleation at higher temperature (190 °C) could be transformed into mordenite crystals during crystallization at lower temperature (150 °C). When the Na2O/SiO2 ratio was ≤ 0.18, a product containing both ZSM-5 and mordenite crystals was obtained during nucleation at higher temperature that could be transformed into ZSM-5 crystals during crystallization at lower temperature. A precondition for crystal transformation between ZSM-5 and mordenite was that the crystallinity of the product formed during nucleation at higher temperature must be ≤ 30%.

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Liquid Phase Hydrogenation of Nitrobenzene over Nickel Supported on Titania K. Joseph Antony RAJ, M. G. PRAKASH, R. MAHALAKSHMY, T. ELANGOVAN, B. VISWANATHAN 2012, 33 (8):  1299-1305.  DOI: 10.1016/S1872-2067(11)60398-7 Abstract ( 2394 )   [Full Text(HTML)] () PDF (432KB) ( 1949 )   The catalytic hydrogenation of nitrobenzene to aniline employing nickel impregnated on rutile, anatase, and high surface area titania supports has been investigated. The nickel is present in elemental state as fcc phase on the catalyst as evidenced by X-ray diffraction results. The Ni crystallite size was found to be greater for Ni/anatase. The temperature-programmed reduction results suggest a greater metal-support interaction for Ni/rutile. The observed order of catalytic activity for the hydrogenation of nitrobenzene is Ni/rutile > Ni/anatase > Ni/TiO2. A conversion of 99% was observed for Ni/rutile at 140 oC and hydrogen pressure of 1.96 MPa. Interestingly, aniline is the only product formed which demonstrates the catalytic hydrogenation of nitrobenzene proceeds with atom economy. Both Ni/rutile and Ni/anatase exhibited a better stability than Ni/TiO2. The hydrogenation proceeds with the preferential adsorption of hydrogen on nickel present in the catalyst surface, possibly assisted by TiOx species.

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Kinetics of Oxidation of L-Leucine by Mono- and Bimetallic Gold and Silver Nanoparticles in Hydrogen Peroxide Solution P. VENKATESAN, J. SANTHANALAKSHMI 2012, 33 (8):  1306-1311.  DOI: 10.1016/S1872-2067(11)60410-5 Abstract ( 2209 )   [Full Text(HTML)] () PDF (454KB) ( 973 )   The catalytic activity of surfactant stabilized mono- and bimetallic Au and Ag nanoparticles for the oxidation of an amino acid, L-leucine, was studied using hydrogen peroxide as the oxidant. The Au and Ag nanoparticle catalysts exhibited very good catalytic activity and the kinetics of the reaction were found to be pseudo-first order with respect to the amino acid. The effects of several factors, such as oxidant concentration, ionic strength, pH, and catalyst concentration on the reaction, were also investigated. In particular, optimal oxidant and catalyst concentrations were determined. Very high concentrations of the metal nano-catalysts or the oxidant led to a dramatic increase in reaction rate. Moreover, bimetallic Au-Ag catalysts provided higher selectivity than pure Au or Ag.

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Synthesis of 2-Amino-4,6-diarylnicotinonitriles Using Silica-Bound N-Propyl Triethylenetetramine Sulfamic Acid as a Recyclable Solid Acid Catalyst Khodabakhsh NIKNAM, Abbas JAMALI, Marzieh TAJADDOD, Abdollah DERIS 2012, 33 (8):  1312-1317.  DOI: 10.1016/S1872-2067(11)60421-X Abstract ( 2716 )   [Full Text(HTML)] () PDF (335KB) ( 1417 )   A simple and efficient procedure for the preparation of silica-bound N-propyl triethylenetetramine sulfamic acid (SBPTETSA) by the reaction of silica-bound N-propyl triethylenetetramine (SBPTET) with chlorosulfonic acid in chloroform is described. Silica-bound N-propyl triethylenetetramine sulfamic acid was employed as a recyclable catalyst for the synthesis of 2-amino-4,6-diarylnicotinonitriles from the multi-component reaction of an acetophenone derivative, an aromatic aldehyde, malononitrile, and ammonium acetate under solvent-free conditions at 100 °C. The heterogeneous catalyst was recycled for five consecutive runs in the optimized multi-component reaction of 4-chloroacetophenone, 4-chloroenzaldehyde, malononitrile, and ammonium acetate without significant loses to its catalytic activity.

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Effect of Structure of CeOHCO3 Precursor of CeO2 on Its Catalytic Performance SUN Ming-Juan, ZOU Guo-Jun, XU Shan, WANG Xiao-Lai 2012, 33 (8):  1318-1325.  DOI: 10.1016/S1872-2067(11)60409-9 Abstract ( 2201 )   [Full Text(HTML)] () PDF (864KB) ( 854 )   A modified hydrothermal process method based on using urea instead of water as the solvent was used to prepare CeOHCO3. Pure CeOHCO3 with a single crystalline structure was produced by varying the experimental conditions. CeO2 particles obtained from these CeOHCO3 precursors were tested for CH4 oxidation. The temperatures for 90% methane conversion were 604 and 647 °C for CeO2 catalysts obtained from hexagonal and orthorhombic CeOHCO3, respectively, indicating that the CeO2 catalyst from hexagonal CeOHCO3 (CeO2-A) was more active than that from the orthorhombic form (CeO2-D). The specific surface area and pore volume of CeO2-A were 45 m2/g and 0.35 cm3/g, respectively, which were higher than those of CeO2-D. H2-TPR showed a much lower reduction temperature and enhanced reducibility with CeO2-A. XPS and O2-TPD results demonstrated there were more oxygen vacancies on the surface of CeO2-A than on CeO2-D, which implied increased oxygen mobility. The CeOHCO3-structure dependent activity was investigated and found to originate from the morphologies of the CeOHCO3 precursors. Hexagonal CeOHCO3 had a rod-like shape while orthorhombic CeOHCO3 had a sphere-like morphology. After calcination, the obtained CeO2 had the morphology of the precursor. The difference in morphology gave CeO2 catalysts with different texture, structure, reducibility, and thus catalytic activity.

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Nano Silica with High Surface Area from Rice Husk as a Support for 12-Tungstophosphoric Acid: An Efficient Nano Catalyst in Some Organic Reactions Ezzat RAFIEE, Shabnam SHAHEBRAHIMI 2012, 33 (8):  1326-1333.  DOI: 10.1016/S1872-2067(11)60420-8 Abstract ( 2451 )   [Full Text(HTML)] () PDF (276KB) ( 2674 )   Nano silica was prepared from rice husk with high surface area. X-ray diffraction (XRD) pattern showed that the amorphous form of silica was produced. Chemical composition of the nano silica was estimated by X-ray fluorescence spectroscopy and CHN analysis. The nano silica was used as a support for H3PW12O40. The nano silica and nano silica supported H3PW12O40 were characterized by inductively coupled plasma, XRD, transmission electron microscopy (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy. TEM images of nano silica as well as the supported catalyst displayed average size of 6 and 7 nm, respectively. The catalyst showed excellent activity in some important organic reactions including Biginelli, Hantzsch, Mannich, and Claisen-Schmidt reactions with good reusability. Catalytic activity of this nano catalyst is an improvement over the commercially available silica that is used to support H3PW12O40.

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Low Cost Synthesis of 3D Flowerlike Co3O4 Nanostructures as Active Catalyst for CO Oxidation CAO Chang-Yan, DOU Zhi-Feng, LIU Hua, SONG Wei-Guo 2012, 33 (8):  1334-1339.  DOI: 10.1016/S1872-2067(11)60408-7 Abstract ( 2643 )   [Full Text(HTML)] () PDF (996KB) ( 997 )   3D flowerlike Co3O4 nanostructures were prepared by a microwave-assisted hydrothermal method, which is a rapid, template-free, and low cost method. The product is obtained in two minutes using all inorganic precursors. The precursor concentration and gradual hydrolysis of urea determine the morphology of Co3O4 nanostructures. These flowerlike Co3O4 nanostructures have high surface area and expose largely active (110) planes, leading to relative high catalytic activity in CO oxidation.

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Oxidation of Biodiesel Glycerol over Pt Supported on Different Sized Carbon Supports in Base-Free Solution ZHANG Meng-Yuan, LIANG Dan, NIE Ren-Feng, Lü Xiu-Yang, CHEN Ping, HOU Zhao-Yin 2012, 33 (8):  1340-1346.  DOI: 10.1016/S1872-2067(11)60411-7 Abstract ( 2676 )   [Full Text(HTML)] () PDF (1393KB) ( 975 )   Recent progress in the selective oxidation of biodiesel glycerol in aqueous solution by Au, Pt and alloy catalysts was reviewed. A series of Pt catalysts on different sized carbon supports were prepared and characterized by scanning electron microscopy, N2 adsorption, transmission electron microscopy, and X-ray powder diffraction. The average particle size of the carbon supports was decreased from 253.2 to 9.3 μm by ball milling, but their surface area and pore volume were only slightly changed. Pt was highly dispersed on these different sized carbon supports with an average particle size between 2.8–5.0 nm. Glycerol oxidation was catalyzed by these highly dispersed Pt catalysts in a base-free aqueous solution. The activity of the Pt catalysts increased with decreasing particle size of the carbon support, which was attributed to the higher accessibility of reactants to the Pt nanoparticles. The best yield of glyceric acid reached 46.7% and the catalyst was stable during six recycles.

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Photocatalytic Synthesis of Phenol by Direct Hydroxylation of Benzene by a Modified Nanoporous Silica (LUS-1) under Sunlight Ghasem SHIRAVAND, Alireza BADIEI, Ghodsi Mohammadi ZIARANI, Morteza JAFARABADI, Majid HAMZEHLOO 2012, 33 (8):  1347-1353.  DOI: 10.1016/S1872-2067(11)60422-1 Abstract ( 2840 )   [Full Text(HTML)] () PDF (474KB) ( 1280 )   Fe-g-C3N4-LUS-1 was prepared by the thermal decomposition of dicyandiamide inside the pores of LUS-1 under an inert atmosphere. It was used as a photocatalyst for the hydroxylation of benzene to phenol in sunlight. The catalysts were characterized by Fourier transform infrared spectroscopy, N2 adsorption-desorption, X-ray diffraction, and scanning electron microscopy. In Fe-g-C3N4-LUS-1, a single layer of graphitic carbon nitride (g-C3N4) was formed on the surface of LUS-1. The photocatalytic activity of the iron containing g-C3N4 based catalysts was investigated, and the catalytic activity was remarkably enhanced when the reaction condition was changed from dark to sunlight. The best result was obtained with 20%Fe-g-C3N4-LUS-1 in sunlight.

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Effect of Ni Addition on Methane Catalytic Combustion Performance of Pd/Al2O3 Catalyst LIU Ying, WANG Sheng, GAO Dian-Nan, WANG Shu-Dong 2012, 33 (8):  1354-1359.  DOI: 10.3724/SP.J.1088.2012.20340 Abstract ( 2541 )   [Full Text(HTML)] () PDF (454KB) ( 1117 )    Pd/Al2O3 catalyst samples modified by Ni promoter were prepared and tested for methane catalytic combustion under lean-fuel condition. A series of Pd catalyst samples with different Ni contents were characterized by N2 adsorption, X-ray diffraction, temperature-programmed reduction, temperature-programmed desorption of ammonia and transmission electron microscopy. In addition, the performance of the catalyst samples for lean methane combustion was studied. The results showed that the addition of Ni effectively improved the activity and hydrothermal stability of catalyst samples due to the formation of NiAl2O4 spinel. As Ni content increased, the NiAl2O4 content increased, thus the performance of the catalyst increased. For Pd/Ni-Al2O3 sample with 20% Ni, methane conversion remained 97.5% after 150 h at 600 oC. Weaker acidity of the supports and the well dispersion of Pd particles on the supports contributed by NiAl2O4 phase might be the reason of high performance of the catalyst.

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Improved Synthesis of SBA-15 Mesoporous Silica Fitting for Industrial Production LI Yan-Rong, SONG Ming-Juan, GU Hai-Fang, HUANG Yao, NIU Guo-Xing, ZHAO Dong-Yuan 2012, 33 (8):  1360-1366.  DOI: 10.3724/SP.J.1088.2012.20317 Abstract ( 2765 )   [Full Text(HTML)] () PDF (569KB) ( 976 )   On the basis of scale-up synthesis of SBA-15 silica in 100 L and 2 m3 reactors, some improved methods were used to prepare SBA-15 silica by crystallizing under high ratio of SiO2/H2O, recycling mother liquid, and using the industrial raw material of TEOS as Si source. It is necessary to openly heat the mother liquid over 95 oC for 2 h to evaporate ethanol and distill the industrial material of TEOS to remove the fractions less than 163 oC before they are used. By these ways, almost no wastes of acid and water are discharged; 50% of P123 and 90% of HCl are saved, respectively, and the cost of SBA-15 greatly drops to 40% of the original. Furthermore, the preparation efficiency increases as twice as before. Therefore, they have great advantages in industrial production of SBA-15 silica for the purposes of environmental protection and cost control.

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Theoretical Study of Reaction Mechanism of Cyclohexene Aromatization over H-ZSM-5 Zeolite ZUO Shi-Ying, ZHOU Dan-Hong, REN Jue, WANG Feng-Jiao 2012, 33 (8):  1367-1373.  DOI: 10.3724/SP.J.1088.2012.20346 Abstract ( 2210 )   [Full Text(HTML)] () PDF (420KB) ( 979 )   By using the QM/MM hybrid ONIOM2 (B3LYP/6-31G(d,p):UFF) method, the dehydro-aromatization reaction of cyclohexene over H-ZSM-5 zeolite was studied. The calculation was based on the 76T cluster model with Al substituted at the T12 site. The results indicated that cyclohexene was adsorbed on the Brönsted acid (B-acid) site of H-ZSM-5 zeolite. The dehydrogenation reaction consisted of cleavage of a C-H bond by acidic proton. After release of dihydrogen, the cabonium moiety was bonded with the basic framework oxygen, resulting in surface cyclohexene alkoxide intermediate. Then the alkoxide released the proton to the framework oxygen which led to generation of B-acid site, and the produced cyclodihexene was adsorbed on the B-acid site. After subsequent dehydrogenation and deprotonation steps, a benzene molecule was produced as final product. The activation energy for dehydrogenation steps was 279.64 and 260.21 kJ/mol, respectively, and the activation energy for deprotonation process was 74.64 and 59.14 kJ/mol, respectively. All dehydrogenation steps are endothermic to lead to surface alkoxide intermediates, and the subsequent deprotonation have lower energy barriers and are exothermic. In addition, the three competitive reactions of cyclohexene, i.e. protonation, hydrogen exchange, and dehydrogenation, were also compared. It was found that cyclohexene preferred to dehydrogenate with zeolite proton.

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Preparation and Characterization of Ni-La-B Amorphous Alloy Catalyst for Low-Pressure Dinitrotoluene Hydrogenation YAN Shao-Wei, FAN Hui, LIANG Chuan, LI Zhong, YU Zhi-Hui 2012, 33 (8):  1374-1382.  DOI: 10.3724/SP.J.1088.2012.20324 Abstract ( 2558 )   [Full Text(HTML)] () PDF (1097KB) ( 899 )   Ni-La-B amorphous alloy catalyst was prepared by KBH4 reduction for liquid phase hydrogenation of dinitrotoluene (DNT) to diaminotoluene (DAT). The effect of La content on microstructure and catalytic performance of Ni-La-B amorphous alloy catalyst for DNT hydrogenation was investigated. The catalyst was characterized by X-ray diffraction, transmission electron microscopy, differential scanning calorimetry, X-ray photoelectron spectroscopy, inductively coupled plasma emission spectroscopy, and H2 temperature-programmed desorption. The results showed that the addition of La could enhance the degree of long-range disorder, reduce the particle diameter from 70 to 10 nm, weaken the strength of Ni–H bond, and improve the thermal stability and antioxidation. The increasing of La addition from 0 to 6% (molar fraction) led to the enhancement of catalytic performance. When the addition of La was 0.6%, Ni-La-B catalyst exhibited the highest performance for low-pressure (1 MPa) DNT hydrogenation, the conversion of DNT and selectivity for DAT reached 100%. Further increasing of La addition from 6% to 8% led to decrease of the surface Ni content and the catalytic activity obviously.

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Synthesis of ZSM-5 Zeolite by Vapor-Phase Method and Performance of Its Mo-Based Catalyst for Methane Dehydroaromatization WANG Di-Yong, WANG Jin-Qu, YANG Jian-Hua, LU Jin-Ming, YIN De-Hong, ZHANG Yan 2012, 33 (8):  1383-1388.  DOI: 10.3724/SP.J.1088.2012.20309 Abstract ( 2164 )   [Full Text(HTML)] () PDF (579KB) ( 904 )   ZSM-5 zeolite was prepared from the amorphous SiO2:Al2O3:TPAOH:Na2O system in H2O vapor phase. The obtained samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, etc. Compared with the hydrothermal method, using the vapor-phase method could easily synthesize ZSM-5 zeolite with uniform particle size. The particle size was between 150 and 250 nm. It also showed a better catalytic performance with CH4 conversion as high as 17.5% and better life time.

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Catalytic Performance of HZSM-5 Molecular Sieve for Synthesis of Polyoxymethylene Dimethyl Ethers GAO Xiao-Chen, YANG Wei-Min, LIU Zhi-Cheng, GAO Huan-Xin 2012, 33 (8):  1389-1394.  DOI: 10.3724/SP.J.1088.2012.20337 Abstract ( 2402 )   [Full Text(HTML)] () PDF (723KB) ( 1183 )   Polyoxymethylene dimethyl ethers (PODEn) were synthesized using methanol (MeOH) and trioxymethylene (TRI) as raw materials. Catalytic performance of acidic molecular sieve HZSM-5 catalyst and PODEn selectivity were found to be strongly dependent on silica/alumina ratio, particle size, phosphorus modified and etc. A series of HZSM-5 zeolite samples modified with various contents of phosphorus were prepared by impregnation with an ammonium dihydrogen phosphate. The crystal structure, pore structure, and surface acidity of the catalyst were studied by various characterization techniques such as X-ray diffraction, N2-adsorption, and temperature-programmed desorption of NH3. Under the mild reaction conditions of 130 °C and raw materials mass ratio MeOH/TRI = 2, methanol conversion and the PODEn (n = 2–5) selectivity were 95.2% and 62.9%, respectively, by using the Pd-modified HZSM-5 catalyst with the optimum conditions (molar ratio of Si to Al was 50, particle size was 5 μm, low-P2O5 content (w = 0–6%) for the preparation). Catalytic performance of HZSM-5 was higher than that of reference commercial catalysts.

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Effects of P Doping Amount on Structure and Photocatalytic Performance of TiO2 for H2 Production from Glycerol Solution TIAN Ye, SANG Huan-Xin, WANG Xi-Tao 2012, 33 (8):  1395-1401.  DOI: 10.3724/SP.J.1088.2012.20353 Abstract ( 2158 )   [Full Text(HTML)] () PDF (754KB) ( 1063 )    Using tetrabutyl-titanate and sodium dihydrogen phosphate as raw materials, TiO2 and P5+-doped TiO2 semiconductors were prepared by the sol-gel method. Their pore distribution, crystal structure, surface compositions, and photoabsorption properties were investigated by N2 adsorption-desorption, X-ray diffraction, Fourier transform infrared spectroscopy, FT-Raman, transmission electron microscopy and UV-Vis diffuse reflectance spectrum. The results show that P5+-doped TiO2 exists in nano-particles of anatase phase with mesoporous structure. P5+-doped TiO2 samples exhibit much smaller crystallite size and much higher specific surface area than pure TiO2. P-doped TiO2 samples show an extension of light absorption into the visible region, which mainly originates from the doping process with the formation of new energy level of P5+ between conductor band and valence band of TiO2 to reduce the energy gap and the electron-hole recombination rate. The P5+-doped TiO2 samples display improved photocatalytic activity for H2 production from glycerol solution, and 5% P5+-doped TiO2 shows a maximum H2 production rate of 1838 μmol/(g·h) under UV irradiation and 209 μmol/(g·h) under simulated-solar irradiation, respectively, which is related to the decrease of crystal particles, increase of specific surface area, and the reduce of the energy gap and the electron-hole recombination rate.

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Fabrication of Fe2O3/TiO2 Nanotube Electrode and Its Photoelectrocatalytic Performance in Dye Wastewater Degradation CONG Yan-Qing, LI Zhe, ZHANG Yi, WANG Qi, XU Qian, FU Fang-Xia 2012, 33 (8):  1402-1409.  DOI: 10.3724/SP.J.1088.2012.20429 Abstract ( 2517 )   [Full Text(HTML)] () PDF (804KB) ( 1432 )   The Fe2O3/TiO2 nanotubes electrode was prepared using cathodically electrochemical deposition and anodic oxidation method. The properties of the composite electrode were characterized by scanning electron microscopy, transmission electronic microscope, X-ray diffraction, and UV-Vis diffuse reflectance spectroscopy. The decolorization of methyl orange was investigated using the composite electrode as a photoanode. The results indicated that Fe2O3 nanoparticles were uniformly dispersed on the surface of TiO2 nanotubes electrode. The adsorption edge of the composite electrode exhibited a red shift compared with the pure TiO2 nanotubes electrode. In addition, Fe2O3/TiO2 nanotubes electrode showed higher current density than TiO2 nanotubes electrode under irradiation. It indicated that the metal oxide modification successfully broadened the absorption spectrum of TiO2 nanotubes to the visible light region. Moreover, it was in favor of the separation of photo-induced electron-hole pairs. The Fe2O3/TiO2 nanotubes electrode performed higher photoelectrocatalytic activity for the degradation of methyl orange. Furthermore, it was found that methyl orange had a higher decolorization rate under the acidic condition. When the initial pH value was 3, the decolorization rate of methyl orange solution could reach 91.7% under the light irradiation for 5 min.

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Effect of Phosphorus on Structure and Performance of Cu/Al2O3 Catalysts for Hydrogenolysis of Glycerol ZHAO Lan-Lan, CHEN Ji-Xiang 2012, 33 (8):  1410-1416.  DOI: 10.3724/SP.J.1088.2012.20455 Abstract ( 2399 )   [Full Text(HTML)] () PDF (613KB) ( 834 )   Phosphorus (P) modified Cu/Al2O3 catalyst was prepared by the successive impregnation method. The physicochemical properties of the catalyst were studied by means of N2 adsorption-desorption, X-ray diffraction, infrared spectroscopy, UV-visible diffuse reflectance spectroscopy, H2 temperature-programmed reduction, NH3 temperature-programmed desorption, and dissociative N2O adsorption. The effects of the P content and the impregnation sequence on the structure and the performance of the catalyst for the hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) were discussed. The addition of P to Cu/Al2O3 enhanced the acidity and Cu dispersion, especially when P species was impregnated prior to Cu. Also, there was a strong interaction between P and Cu species. However, the strong interaction leads to the coverage of Cu atoms with the P species at high P content. The coverage may be more serious when the P species was added after Cu to the catalyst. In the hydrogenolysis of glycerol, the addition of P prior to Cu remarkably promoted the catalytic performance of Cu/Al2O3. Under the conditions of 220 ºC, 3.0 MPa, space velocity of 2.0 h-1, and the H2/glycerol molar ratio of 20, as the P content increased from 0 to 6%, the glycerol conversion and the 1,2-PDO selectivity increased from 17.1% to 95.0% and from 83.7% to 97.2%, respectively. The promotion effect of P on the performance of Cu/Al2O3 is attributed to the increase of catalyst acidity as well as the strong interaction between Cu and P species.

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Photocatalytic Properties of Activated Carbon-NiFe2O4 Magnetic Catalyst FENG Lian-Rong, HU Feng-Tian, LIU Cheng-Bao, CHEN Feng, XU Nan, LIU Shou-Qing, CHEN Zhi-Gang 2012, 33 (8):  1417-1422.  DOI: 10.3724/SP.J.1088.2012.20348 Abstract ( 2430 )   [Full Text(HTML)] () PDF (476KB) ( 1255 )   Activated carbon-nickel ferrite (AC-NiFe2O4) has been successfully synthesized using activated carbon, NiSO4·6H2O, and FeCl3·6H2O as the raw materials by the hydrothermal method at 180 oC for 10 h. The as-synthesized sample was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. The photo-Fenton degradations of model pollutants methylene blue, rhodamine B, and malachite green were conducted in the presence of oxalic acid using AC-NiFe2O4 as photo-Fenton catalyst under λ > 400 nm visible light. The results showed that the AC-NiFe2O4 catalyst can effectively decompose the organic pollutants under visible light irradiation and the degradation ratio of organic pollutants in the concentration of 20.0 mg/L reached over 90% in 10 h, whereas the NiFe2O4 catalyst appeared no photocatalytic activity under the similar conditions. The catalytic activity did not exhibit significant loss after 8 runs, showing the potential application of AC-NiFe2O4 as an effective photo-Fenton catalyst to degrade organic pollutions.

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In-Situ Liquid Phase Catalytic Hydrogenation for One-Pot Synthesis of Quinolines from Aromatic Nitro Compounds GU Hui-Zi, XU Xiang-Sheng, CHEN Ao-Ang, YAN Xin-Huan 2012, 33 (8):  1423-1426.  DOI: 10.3724/SP.J.1088.2012.20341 Abstract ( 2231 )   [Full Text(HTML)] () PDF (533KB) ( 827 )   A new hydrogenation system was proposed for the synthesis of quinolines. Aromatic nitro compounds and ethanol/water solution were used as the starting materials, and Pt-Sn/γ-Al2O3 was the catalyst. The quinolines were synthesized by the one-pot method with an in-situ liquid phase hydrogenation system. The reaction results showed that the Pt/Sn molar ratio and the reaction conditions including temperature and the concentration of the substrate and water played an important role on the yield of the quinolines. When the Pt/Sn molar ratio was 0.5, under the conditions of 220 oC, 5.0 MPa, 6% substituted nitrobenzene concentration with 70% EtOH and 30% H2O solution, the total yield of 6-methoxyl-2-methyl quinoline reached 72.0%.

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Effect of Pd Doping on Water Dissociation on ZnO(1120) Surface GU Xiang-Kui, DING Wu-Chen, HUANG Chuan-Qi, LI Wei-Xue 2012, 33 (8):  1427-1431.  DOI: 10.3724/SP.J.1088.2012.20526 Abstract ( 2202 )   [Full Text(HTML)] () PDF (344KB) ( 688 )   Water monomer adsorption and dissociation on clean and Pd-doped ZnO(1120) surface were investigated by using density functional theory calculations. It was found that water monomer on clean ZnO(1120) prefers the molecular adsorption rather than dissociation. However, its dissociation on Pd-doped ZnO became exothermic with reaction energy of -0.21 eV and kinetically facile with barrier of 0.36 eV, due to enhanced bonding strength of the product OH and H.