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Chinese Journal of Catalysis
2013, Vol. 34, No. 5
Online: 06 May 2013


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This special issue is dedicated to Professor Jingfa Deng in memory of his 80th birthday. Mr. Jingfa Deng (1933–2001) was a famous physical chemist and chemistry educator who devoted himself to research and teaching in the fields of physical chemistry, heterogeneous catalysis, and surface chemistry. He was mentoring many young scholars and made prominent contributions to raising the research in metal catalysis and new catalytic materials in China to the advanced level world-wide.

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Table of Contents for Vol. 34 No. 5 2013, 34 (5):  0-0.  Abstract ( 440 )   PDF (2988KB) ( 627 )

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Preface to Special Issue of Chinese Journal of Catalysis in Memory of the 80th Birthday of Professor Jingfa Deng FAN Kang-Nian, BAO Xin-He, XU Guo-Qin 2013, 34 (5):  817-819.  DOI: 10.1016/S1872-2067(12)60593-2 Abstract ( 798 )   [Full Text(HTML)] () PDF (296KB) ( 788 )

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Brief biography of Jingfa Deng QIAO Minghua, XU Guoqin, FAN Kangnian 2013, 34 (5):  820-827.  DOI: 10.1016/S1872-2067(12)60594-4 Abstract ( 814 )   [Full Text(HTML)] () PDF (764KB) ( 839 )

Reviews

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Research, development, and application of amorphous nickel alloy catalysts prepared by melt-quenching ZONG Baoning, MU Xuhong, ZHANG Xiaoxin, MENG Xiangkun, QIAO Minghua 2013, 34 (5):  828-837.  DOI: 10.1016/S1872-2067(11)60486-5 Abstract ( 765 )   [Full Text(HTML)] () PDF (448KB) ( 1220 )   Raney Ni is one of the most widely used catalysts in the petrochemical industry. This material's intrinsic catalytic activity for hydrogenation may be enhanced by transforming the crystalline Ni-based alloy into an amorphous structure via melt-quenching. The meta-stability and low specific surface area of such amorphous alloys, however, can severely restrict their catalytic applications. Our work has demonstrated that the incorporation of rare earth (RE) elements increases the crystallization temperature of an amorphous Ni catalyst by 200 K. Related experimentation has determined that the specific surface area of such catalysts is dramatically increased by two orders of magnitude following alloying with Al and subsequent caustic leaching. In addition, by introducing a third metal as a promoter, the hydrogenation selectivity, corrosion resistance and magnetism of these materials may be precisely adjusted, giving rise to a family of skeletal amorphous Ni alloy catalysts, to which we apply the trade name SRNA. Among these catalysts, the SRNA-1 catalyst is used for the hydrogenation of pharmaceutical intermediates, SRNA-2 is employed for the hydrogenation of glucose into sorbitol, SRNA-3 is effective in the adsorptive desulfurization of gasoline and diesel and SRNA-4 is used for the purification of caprolactam. In addition, the SRNA-5 catalyst is useful in the hydrogenation of benzoic acid as a partial substitute for the costly Pd/C catalyst, reducing consumption of the latter during the hydrogenation process by almost 50%.

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Tuning the shape of ceria nanomaterials for catalytic applications TA Na, LIU (Jimmy) Jingyue, SHEN Wenjie 2013, 34 (5):  838-850.  DOI: 10.1016/S1872-2067(12)60573-7 Abstract ( 1012 )   [Full Text(HTML)] () PDF (2044KB) ( 1585 )   The design and fabrication of catalytic materials is a key issue in heterogeneous catalysis to achieve desired performance. Traditionally, the main theme is to reduce the size of the catalyst particles as small as possible for increasing the number of active sites. In recent years, the rapid advancement in materials science has enabled us to fabricate catalyst particles with tunable shape at nanometer level. Through morphology control of nanoparticles by exposing highly reactive crystal planes, their catalytic properties can be drastically enhanced. Therefore, both size modulation and shape control of catalyst nanoparticles can be achieved independently or synergistically to optimize their catalytic behavior. We highlight, in this review, the recent progress in shape control of CeO2 materials that are widely used as crucial components or structural and electronic promoters in heterogeneous catalysts. We first summarize the major synthetic strategies and characteristics of shape-controlled CeO2 nanomaterials. We then survey morphology-dependent nanocatalysis of CeO2 and Au-CeO2 catalysts. We understand now that the enhanced catalytic property of the Au-CeO2 system is closely related to the unique interaction between the gold nanoparticles and the ceria support; such an interaction originates from the particular shape of ceria, especially the exposed facets. Finally, we present our understanding of the morphology-dependent nanocatalysis and provide our perspectives on their future potential and development. The fundamental understanding of the nature of the intrinsic active sites of the shape-tunable ceria nanostructures, enclosed by reactive crystal planes/facets with unique properties, is expected to provide highly efficient nanocatalysts for practical applications.

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Interactions among supported copper-based catalyst components and their effects on performance: A review DONG Lin, YAO Xiaojiang, CHEN Yi 2013, 34 (5):  851-864.  DOI: 10.1016/S1872-2067(12)60592-0 Abstract ( 760 )   [Full Text(HTML)] () PDF (1026KB) ( 1134 )   Supported copper-based catalysts are widely used in many industrial processes because of their excellent catalytic performance and low cost. Understanding the interactions among the various components of these catalysts is an important step in exploring the nature of the catalytic reactions and provides a valuable scientific basis for the design of novel and efficient catalysts. This review summarizes a number of our recent results in this field. In this work, copper oxide was loaded on CeO2, CexZr1-xO2, and MoO3-CeO2 supports to produce model catalysts. Investigations involving these materials demonstrated that the dispersion of copper oxide on the surface of the oxide supports, as well as some of the properties of these catalysts, can be explained on the basis of the incorporation model, which we have previously proposed. Based on spectroscopic characterization of these catalysts and examination of their catalytic performance for the oxidation of CO or the selective catalytic reduction of NO with CO/NH3, the relationships among the compositions, structures, and properties of these catalysts are discussed.

Communications

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Effect of photon irradiation on the adsorption of CO2 on polycrystalline Cu WANG Shuai, XU Guoqin 2013, 34 (5):  865-870.  DOI: 10.1016/S1872-2067(12)60538-5 Abstract ( 711 )   [Full Text(HTML)] () PDF (515KB) ( 779 )   The adsorption and photochemistry of CO2 on ordered/disordered Cu surfaces were investigated using X-ray photoelectron and high resolution electron loss technique. Physisorbed CO2 and chemisorbed CO2δ- species were isolated on different faces. Studies on the photochemical behavior of physisorbed and chemisorbed species were conducted with 193 nm laser irradiation. No photoinduced reaction occurred with the physisorbed species. Photoinduced dissociation was seen with chemisorbed species.

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Activated carbon-supported ruthenium as an efficient catalyst for selective aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran NIE Junfang, XIE Jiahan, LIU Haichao 2013, 34 (5):  871-875.  DOI: 10.1016/S1872-2067(12)60551-8 Abstract ( 869 )   [Full Text(HTML)] () PDF (441KB) ( 1073 )   The aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) was per-formed on an activated carbon-supported ruthenium (Ru/C) catalyst. The excellent DFF yield of 95.8% was achieved at 383 K and O2 pressure 2.0 MPa in toluene. It exhibited superior activity and DFF selectivity than other C-supported noble metals (i.e. Pt, Rh, Pd, and Au) with comparable nanoparticle size. The Ru/C catalyst was stable and can be recycled by a simple hydrothermal treatment. Moreover, the product distribution in the HMF oxidation on Ru/C can be tuned by the use of water as solvent and the addition of hydrotalcite, giving either 5-formyl-2-furancarboxylic acid or 2,5-furandicarboxylic acid as the dominant product.

Articles

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Catalytic performance of different types of iron zeolites in N2O decomposition WANG Junying, XIA Haian, JU Xiaohua, FAN Fengtao, FENG Zhaochi, LI Can 2013, 34 (5):  876-888.  DOI: 10.1016/S1872-2067(12)60555-5 Abstract ( 719 )   [Full Text(HTML)] () PDF (781KB) ( 982 )   A series of Fe/zeolites (ZSM-35, ZSM-5, beta, and mordenite) samples with Fe/Al molar ratios of 0.33 were prepared using a solid-state ion-exchange method. A combination of ultraviolet-visible diffuse reflectance, in-situ Fourier-transform infrared, and in-situ visible Raman spectroscopic techniques, with a transient response method, was used to investigate the influence of the zeolite framework on the catalytic properties of the Fe/zeolites in N2O decomposition. The results show that the catalytic activity of the Fe/zeolites-HT (HT denotes high-temperature treatment) samples is in the order Fe/ZSM-35-HT > Fe/beta-HT > Fe/ZSM-5-HT > Fe/mordenite-HT. There is a linear relationship between the rate of N2O decomposition and the concentration of binuclear iron sites. This indicates that binuclear iron sites are the active sites for N2O decomposition. A correlation between the formation of binuclear iron sites and Fe ion distribution among the cationic sites is proposed. Two Fe(II) cations located in two adjacent six-membered rings in a 10-membered ring channel (α sites) or in two neighboring six-membered rings in an eight-membered ring channel (β sites) of Fe/ZSM-35 are favorable for the formation of active binuclear iron sites. Similar structure can also be formed in two adjacent six-membered rings in polymorphs A and B of beta zeolite or in the six-membered rings at the intersection of the straight and sinusoidal channels of the ZSM-5 framework. For the Fe/mordenite-HT sample, most of the iron species are present as isolated iron cations, so it has the lowest activity in N2O decomposition.

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Dynamic structural changes of perovskite-supported metal catalysts during cyclic redox treatments and effect on catalytic CO oxidation GAO Kang, WEI Mingming, QU Zhenping, FU Qiang, BAO Xinhe 2013, 34 (5):  889-897.  DOI: 10.1016/S1872-2067(12)60581-6 Abstract ( 851 )   [Full Text(HTML)] () PDF (750KB) ( 978 )   CaTiO3-and BaTiO3-supported Ag and Pt catalysts were subjected to cyclic oxidation and reduction treatments and their surface structures were investigated using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The CO oxidation reactions over the Ag and Pt catalysts showed that the oxidized Ag/oxide catalysts performed better in CO oxidation than the reduced ones did, whereas the reduced Pt/oxide catalysts had higher CO oxidation activity than that after oxidation treatment. The XRD and XPS measurements revealed that the oxidation treatment helped to improve the dispersion of Ag nanoparticles, but their metallic state was retained, which enhanced CO oxidation. In contrast, the surfaces of the Pt nanoparticles were dominated by PtO2 after the oxidation treatment, which lowered the CO oxidation activity compared with that of the reduced Pt catalyst.

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Influence of preparative method on Al2O3-doped Pt/WO3-ZrO2 catalyst for n-heptane isomerization SHANG Shuning, XU Xin, XIE Pengfei, YUE Yinghong, HUA Weiming, GAO Zi 2013, 34 (5):  898-905.  DOI: 10.1016/S1872-2067(12)60540-3 Abstract ( 741 )   [Full Text(HTML)] () PDF (550KB) ( 1112 )   Alumina-doped Pt/WO3/ZrO2 catalysts were prepared using either a constant or variable pH method. The obtained catalyst samples were characterized using N2 adsorption, X-ray diffraction, ultraviolet-visible diffuse reflectance, CO chemisorption, X-ray photoelectron spectroscopy, 27Al magic-angle spinning nuclear magnetic resonance, and infrared spectroscopy of adsorbed pyridine. Compared to the catalyst prepared using the variable pH method, the catalyst prepared using the constant pH method had a higher surface area and Pt dispersion. More Brönsted acid sites were generated in the presence of H2 on the latter catalyst, and this was responsible for its higher catalytic activity in n-heptane hydroisomerization. When the reaction temperature was 200℃ and the weight hourly space velocity of n-heptane was 0.9 h-1, the Pt/WO3/Al2O3-ZrO2 catalyst prepared using the constant pH method gave 70.0% conversion of n-heptane, which was significantly greater than the conversion obtained using the corresponding catalyst prepared using the variable pH method (43.5%).

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Periodic DFT study of the deep oxidation in the oxidative dehydrogenation of ethane over V2O5 (001) DAI Guoliang, LI Zhenhua, WANG Wenning, LIU Jing, FAN Kangnian 2013, 34 (5):  906-910.  DOI: 10.1016/S1872-2067(11)60523-8 Abstract ( 555 )   [Full Text(HTML)] () PDF (526KB) ( 668 )   The mechanism of the deep oxidation in ethane oxidative dehydrogenation (ODH) over V2O5 (001) was investigated by periodic DFT. In ethane ODH over V2O5 (001), acetaldehyde formation is the main side reaction. Desorbed acetaldehyde can be further easily oxidized to acetic acid. However, before they can desorb from the surface, most of the acetaldehyde species are oxidized to COx. The oxidation product COx mainly comes from the oxidation of acetaldehyde.

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Theoretical study on the dissociative adsorption of CH4 on Pd-doped Ni surfaces ZHAO Yonghui, LI Shenggang, SUN Yuhan 2013, 34 (5):  911-922.  DOI: 10.1016/S1872-2067(12)60565-8 Abstract ( 723 )   [Full Text(HTML)] () PDF (786KB) ( 1018 )   Density functional theory (DFT) was employed to predict the most stable structure of Pd-doped Ni(111), Ni(100), and Ni(211) surfaces, and the activity for CH4 dissociation on pure and Pd-doped Ni surfaces. We predict that the thermodynamically most stable structures are the surface-doped Pd/Ni surfaces, where a surface Ni atom is replaced by a Pd atom; subsurface-doped Pd/Ni surfaces are thermodynamically unstable. Of the surface-adsorbed Pd/Ni surfaces, only the Pd/Ni(211) surface is thermodynamically stable. From the calculated adsorption energies of CH4 dissociation intermediates (CH4, CH3, CH, C and H) on surface-doped Pd/Ni surfaces, we find Pd-doping to reduce the adsorption energy for all species except for CH4. In addition, from the calculated activation barriers for CH4 and CH dissociations, we predict CH4 and CH to dissociate predominately on Ni(211) and Pd/Ni(211) step surfaces, followed by the broad Ni(100) and Pd/Ni(100) surfaces. Pd-doping raises the activation barriers for CH4 and CH dissociations. For the most active Ni(211) surface, Pd-doping causes the CH dissociation step to have a higher activation barrier than the CH4 dissociation step, which changes the rate limiting step, and helps reduce carbon deposition.

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Deactivation mechanism of PdCl2-CuCl2/Al2O3 catalysts for CO oxidation at low temperatures FENG Yafen, WANG Li, ZHANG Yanhui, GUO Yun, GUO Yanglong, LU Guanzhong 2013, 34 (5):  923-931.  DOI: 10.1016/S1872-2067(12)60556-7 Abstract ( 654 )   [Full Text(HTML)] () PDF (587KB) ( 810 )   Supported Wacker catalysts exhibited high activity for low temperature CO oxidation, but high concentrations of water in the reaction gas could lead to the deactivation of the catalyst. The PdCl2-CuCl2/Al2O3 catalysts were prepared, and a high relative humidity deactivation mechanism was suggested after characterizing the fresh and spent catalyst by X-ray diffraction, N2 absorption-desorption, X-ray photoelectron spectroscopy, H2-temperature programmed reduction and in situ diffuse reflectance infrared Fourier transform spectroscopy. The results showed that the water could adsorb and condense on the surface of the catalyst, which arouses the aggregation and transfer of Cu species into the internal pores of the catalyst. This weakens the interactions between the Pd and Cu species and reduces the re-oxidation ability of Pd0 to Pd2+, which blocks redox cycling and results in the decrease of CO oxidation activity.

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Carbon-coated mesoporous silica functionalized with sulfonic acid groups and its application to acetalization FANG Lin, ZHANG Kun, CHEN Lu, WU Peng 2013, 34 (5):  932-941.  DOI: 10.1016/S1872-2067(12)60591-9 Abstract ( 680 )   [Full Text(HTML)] () PDF (790KB) ( 846 )   The inner surface of mesoporous silica SBA-15 was coated by a homogeneous polycyclic carbon layer through controlled carbonization of furfuryl alcohol. The composite was subsequently functionalized with sulfonic acid (-SO3H) groups to form a strong solid acid material, with a tunable acid site density in the range of 0.38-0.84 mmol/g by varying the thickness of the carbon layer. Structural analysis and reaction data revealed that the solid acid catalyst exhibited high reactivity towards the acetalization of aldehydes or ketones with alcohols because of the uniform carbon coating of the mesopores, high acid site density, and its mechanical stability.

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Nano-size effect of Au catalyst for electrochemical reduction of oxygen in alkaline electrolyte ZHANG Gui-Rong, XU Bo-Qing 2013, 34 (5):  942-948.  DOI: 10.1016/S1872-2067(12)60546-4 Abstract ( 730 )   [Full Text(HTML)] () PDF (621KB) ( 806 )   Oxygen reduction reaction (ORR) in alkaline electrolyte (0.5 mol/L KOH) was studied on a series of carbon supported Au nanoparticles (NPs) with average sizes ranging from 3 to 14 nm, using the rotating disk electrode methods. Downsizing the Au NPs from 14 to 3 nm resulted in continued enhancement in both the intrinsic and mass-specific activity of Au for ORR but produced no influence on the reaction mechanism or number of transferred electrons per O2-reduction. Careful analyses of the particle shapes of Au NPs with varied sizes by using high-resolution transmission electron microscopy enabled us to estimate the fraction of surface Au atoms at different positions or coordination (energy) state. Correlating the fraction of high energy surface atoms with the Au activity for ORR disclosed the importance of high energy surface atoms in enhancing the intrinsic activity of Au. Fundamental correlation between the Au intrinsic activity for ORR and the experimentally determined surface electronic structure of Au NPs was also established.

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Preparation and visible light catalytic activity of three-dimensional ordered macroporous CdS/TiO2 films CHEN Xiaofang, ZHANG Jia, HUO Yuning, LI Hexing 2013, 34 (5):  949-955.  DOI: 10.1016/S1872-2067(12)60560-9 Abstract ( 694 )   [Full Text(HTML)] () PDF (783KB) ( 895 )   A three-dimensional ordered macroporous CdS/TiO2 film was prepared by the sol-gel method with a colloidal crystal template and S2- ion exchange, and it exhibited high visible light photocatalytic activity for the aqueous degradation of rhodamine B and 4-chlorophenol. The modification with CdS gave visible light absorption by photosensitization and better separation of photo-induced electrons and holes. The ordered macroporous structure gave higher light utilization and faster reactant transport.

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Hydrogenation of carbon dioxide to light olefins over non-supported iron catalyst YOU Zhenya, DENG Weiping, ZHANG Qinghong, WANG Ye 2013, 34 (5):  956-963.  DOI: 10.1016/S1872-2067(12)60559-2 Abstract ( 931 )   [Full Text(HTML)] () PDF (1347KB) ( 1270 )   The hydrogenation of CO2 to light olefins was investigated over non-supported Fe catalysts. It was found that the addition of alkali metal ions to the Fe catalyst led to significant increases in both the CO2 conversion and the selectivity for olefins. Over K- or Rb-modified catalysts, about 40% CO2 conversion and more than 50% olefin selectivity were obtained. The yield of C2-C4 olefins exceeded 10% over these modified catalysts. Catalyst characterization suggested that the formation of iron carbide species was accelerated by the modification of the Fe catalyst with alkali metal ions, and this enhancement may be one of the key reasons for the enhanced catalytic performance. For the K-modified Fe catalysts, K content has a major influence on the catalyst behavior. An increase in the K content from 1 to 5 wt% increased both CO2 conversion and olefin selectivity. However, too high a K content led to a decrease in the activity, probably because of decreases in the surface area and CO2 chemisorption capacity of the catalyst. The presence of an appropriate amount of B in the K-modified Fe catalyst was found to be beneficial to the olefin selectivity, without significantly decreasing the conversion of CO2.

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XPS and TPD study of NO interaction with Cu(111)：Role of different oxygen species CHEN Bohao, MA Yunsheng, DING Liangbing, XU Lingshun, WU Zongfang, YUAN Qing, HUANG Weixin 2013, 34 (5):  964-972.  DOI: 10.1016/S1872-2067(12)60585-3 Abstract ( 850 )   [Full Text(HTML)] () PDF (861KB) ( 952 )   The adsorption and reaction of NO on clean and O-precovered Cu(111) has been studied using X-ray photoelectron spectroscopy and temperature-programmed desorption spectroscopy. By varying NO exposure and annealing temperature, two different types of chemisorbed oxygen species, with O 1s binding energies (BE) of 531.0 (O531) and 529.7 eV (O529), were prepared on Cu(111). In the presence of O531 species, the relative occupation of different NO adsorption states was largely affected, and most of the adsorbed NO(a) underwent dissociative desorption, releasing N2O and N2 upon heating. In contrast, in the presence of O529 species, the dissociative desorption of NO(a) was largely suppressed. Furthermore, the O529 species show a more significant blocking effect on NO adsorption than the chemisorbed O531 species. Our results reveal that the effect of precovered oxygen species on the adsorption and reaction of NO on Cu(111) is closely related to the type of oxygen species and oxygen coverage.

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A first-principles study of the structure, electronic properties, and oxygen binding of FeO/Pt(111) and FeO2/Pt(111) SUN Dapeng, LI Weixue 2013, 34 (5):  973-978.  DOI: 10.1016/S1872-2067(12)60580-4 Abstract ( 775 )   [Full Text(HTML)] () PDF (501KB) ( 850 )   The ultrathin oxide films of bilayer FeO and trilayer FeO2 superstructures on Pt(111) with periodicity of (√84×√84)R10.9° are studied in detail by density functional theory, and the corresponding structural properties, electronic properties, and oxygen activities in different domains (FCC, HCP, and TOP) are calculated. It is found that for both superstructures, the in-plane lattice constants slightly increase in the order FCC < HCP < TOP. The calculated order of the surface corrugation (O-Fe rumpling) is FCC > HCP > TOP for FeO/Pt(111), and FCC > TOP > HCP for FeO2/Pt(111). The surface electrostatic potentials and the binding energies of the surface oxygen atoms are found to follow the same order as the surface corrugation. There is net charge transfer from the supported FeO film to the Pt substrate for FeO/Pt(111), and the calculated oxidation state of iron is +2.36. In contrast, for FeO2/Pt(111), there is charge transfer from the Pt substrate to the supported FeO2 film, and the calculated oxidation state of iron is +2.95 (ferric state). Compared with Pt(111), the change of the surface work function of FeO/Pt(111) is negligible, while it is 1.24 eV for FeO2/Pt(111). The role of the surface dipole of the supported oxide film and the charge transfer of the ultrathin oxide film are discussed.

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Solvent effects in the synthesis of CoB catalysts on hydrogen generation from hydrolysis of sodium borohydride SHEN Xiaochen, DAI Min, GAO Ming, ZHAO Bin, DING Weiping 2013, 34 (5):  979-985.  DOI: 10.1016/S1872-2067(12)60577-4 Abstract ( 796 )   [Full Text(HTML)] () PDF (1311KB) ( 1288 )   Solvent effects are important in synthetic chemistry, especially in preparing nanosized materials in solution. The sizes, morphologies, and properties of nanoparticles obtained from solution are greatly influenced by the solvents used. CoB catalysts were synthesized in solvents with different viscosity and polarity, including water, methanol, ethanol, and n-propanol. Solvent effects on the size and morphology of CoB were investigated using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen sorption measurements. CoB catalysts possessed non-crystalline structures composed of discrete nanoparticles, but became more agglomerated with increasing solvent viscosity. The hydrolysis of NaBH4 showed that catalyst morphology and texture greatly affected catalytic activity. XPS showed that Co and B were each present in elemental and oxidized states in the CoB catalysts, and that the Co/B surface ratio varied greatly with a higher Co/B ratio resulting in better catalytic properties. Solvent effects were analyzed in terms of steric hindrance and viscosity, and a mechanism for CoB synthesis in the different solvents was proposed.

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Trivalent metal ions M3+ in M0.02Cu0.4Mg5.6Al1.98(OH)16CO3 layered double hydroxide as catalyst precursors for the hydrogenolysis of glycerol XIA Shuixin, ZHENG Liping, NIE Renfeng, CHEN Ping, LOU Hui, HOU Zhaoyin 2013, 34 (5):  986-992.  DOI: 10.1016/S1872-2067(11)60505-6 Abstract ( 797 )   [Full Text(HTML)] () PDF (954KB) ( 832 )   Trivalent metal ions M3+ in M0.02Cu0.4Mg5.6Al1.98(OH)16CO3 (M = Ru, Re) layered double hydroxides (LDHs) were successfully synthesized by coprecipitation. Bimetallic M-Cu/solid base catalysts with high metal dispersion were obtained after calcination and H2 reduction of these LDH precursors. These catalysts exhibited excellent performances for the hydrogenolysis of biomass-derived glycerol under mild conditions. The catalysts were stable when recycled five times. Characterizations indicated that the addition of Ru or Re enhanced the adsorption and activation of hydrogen on the surface of catalysts, which contributed to the high conversion of glycerol.

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Catalytic conversion of biomass-derived levulinic acid into ?-valerolactone using iridium nanoparticles supported on carbon nanotubes DU Xianlong, LIU Yongmei, WANG Jianqiang, CAO Yong, FAN Kangnian 2013, 34 (5):  993-1001.  DOI: 10.1016/S1872-2067(11)60522-6 Abstract ( 863 )   [Full Text(HTML)] () PDF (834KB) ( 1055 )   A new method has been developed for the catalytic conversion of biomass-derived levulinic acid (LA) into γ-valerolactone (GVL) with molecular hydrogen (H2) using a series of heterogeneous noble metal catalysts. Excellent yields of the GVL were obtained under mild reaction conditions of 50℃ and 2 MPa of H2 using iridium nanoparticles supported on carbon nanotubes (Ir/CNT). It is noteworthy that the reaction proceeded smoothly in the presence of formic acid (FA, co-produced with LA in equimolar amounts during the acid-mediated hydrolysis of lignocellulosic biomass). Furthermore, the FA remained intact, highlighting the practical advantages of this process for the convenient and cost-effective processing of a biomass-derived LA/FA solution. The method is effective for the simultaneous production of GVL and FA from a wide variety of renewable biomass resources.

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Density functional theory study of direct synthesis of H2O2 from H2 and O2 on Pd(111), Pd(100), and Pd(110) surfaces TIAN Pengfei, OUYANG Like, XU Xinchao, XU Jing, HAN Yi-Fan 2013, 34 (5):  1002-1012.  DOI: 10.1016/S1872-2067(12)60537-3 Abstract ( 705 )   [Full Text(HTML)] () PDF (982KB) ( 2429 )   The direct synthesis of hydrogen peroxide (H2O2) from hydrogen (H2) and oxygen (O2) on Pd(111), Pd(100), and Pd(110) surfaces was investigated using periodic density functional theory (DFT) calculations. Several elementary steps making up this reaction were postulated and calculated. The Pd(111) surface shows the highest catalytic selectivity for H2O2 among the three surfaces. Open surfaces such as Pd(100) and Pd(110) are not favorable for this reaction because O-O-containing species on these surfaces dissociate easily. The O-O bond energy and the binding energy of O-O-containing surface species are responsible for catalytic selectivity. The higher binding energy of O-O-containing surface species is not favorable for the direct synthesis of H2O2 because the higher binding energy results in lower dissociation barriers.

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Preparation and application of highly efficient Au/SnO2 catalyst in the oxidative lactonization of 1,4-butanediol to γ-butyrolactone LI Xian, ZHENG Jiamin, YANG Xinli, DAI Weilin, FAN Kangnian 2013, 34 (5):  1013-1019.  DOI: 10.1016/S1872-2067(12)60534-8 Abstract ( 734 )   [Full Text(HTML)] () PDF (1259KB) ( 834 )   A series of gold catalysts supported on commercial SnO2 were synthesized by deposition-precipitation while accurately controlling pH and precipitant species. The supported catalysts were characterized by X-ray diffraction, inductively coupled plasma atomic emission spectrometry, transmission electron microscopy, and X-ray photoelectron spectroscopy. Gold loading and calcination temperature both affected the dispersion and nature of gold species on SnO2. The performance of the catalysts in the oxidative lactonization of 1,4-butanediol to g-butyrolactone was investigated. The catalyst with 3% gold that was calcined at 573 K exhibited the highest activity, which was 15 times higher than that of Au/TiO2. The excellent catalytic performance was attributed to the high dispersion of gold particles and adequate Au0 and Auδ- species formed because of the strong interaction between Au and SnO2 and the intrinsic properties of SnO2.

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Physically mixed ZnO and skeletal NiMo for one-pot reforming-hydrogenolysis of glycerol to 1,2-propanediol HU Jiye, LIU Xiaoyu, FAN Yiqiu, XIE Songhai, PEI Yan, QIAO Minghua, FAN Kangnian, ZHANG Xiaoxin, ZONG Baoning 2013, 34 (5):  1020-1026.  DOI: 10.1016/S1872-2067(12)60543-9 Abstract ( 792 )   [Full Text(HTML)] () PDF (608KB) ( 859 )   The one-pot aqueous phase reforming (APR) and hydrogenolysis of glycerol to 1,2-propanediol (PDO) was catalyzed by physically mixed skeletal NiMo and zinc oxide catalysts in a continuous flow fixed-bed reactor without the aid of added H2. The skeletal NiMo catalyst alone is highly active towards glycerol but the selectivity for 1,2-PDO is only moderate. Physically mixing of MgO, SiO2, Al2O3, HZSM-5, TiO2, ZrO2, or CeO2 as a cocatalyst with skeletal NiMo was detrimental to the conversion of glycerol and yield of 1,2-PDO. However, physically mixing with ZnO gave an advantageous promoting effect on both the catalytic activity and selectivity for 1,2-PDO, and gave a 1,2-PDO yield of 52.0%, which is higher than that obtained with noble metal catalysts for the APR-hydrogenolysis of glycerol. The synergistic effect between physically mixed ZnO and skeletal NiMo was attributed to in situ enhancement of the Lewis acidity of ZnO by chemisorbed CO2 from the APR of glycerol on skeletal NiMo, which benefited both the dehydration of glycerol to acetol on ZnO and the hydrogenation of acetol to 1,2-PDO on skeletal NiMo.

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null WANG Yi, XU Liang, XU Lei, LI Hexing, LI Hui 2013, 34 (5):  1027-1032.  DOI: 10.1016/S1872-2067(12)60526-9 Abstract ( 648 )   [Full Text(HTML)] () PDF (604KB) ( 821 )   Mesoporous silica (SBA-15)-supported Ru-B catalyst was synthesized by ultrasound-assisted incipient wetness infiltration of (NH4)2RuCl6 into SBA-15 and a subsequent reduction with BH4-. It was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, differential scanning calorimetry, and transmission electron microscopy. The resulting Ru-B-X/SBA-15 catalyst was identified to be an amorphous alloy highly dispersing within the pore channels of SBA-15. During liquid-phase maltose hydrogenation, the as-synthesized Ru-B-X/SBA-15 catalyst was more active than the Ru-B-C/SBA-15 obtained via the same process but using RuCl3 as the metal source. The as-prepared Ru-B-X/SBA-15 delivered catalytic activity up to seven times greater than that associated with the reference unsupported Ru-B-C catalyst prepared through the reduction of RuCl3 with BH4, and could be used repetitively 11 times without significant deactivation.