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Naoko Inoue, Toshiya Tada, Katsuya Kawamoto
In the gasification of biomass, it is necessary to limit the amount of by-product tar and increase the yields of hydrogen and carbon monoxide (syngas). Therefore, we conducted gasification and reforming experiments on woody biomass using an electric tubular furnace, to evaluate the gas reforming and tar decomposition performance of a NiO/SBA-15 catalyst. As a result, we found that this catalyst is effective for H2 production. It is believed that the increase in H2 volume due to the catalyst occurs through a steam reforming reaction involving hydrocarbons including CH4 , and the water-gas shift reaction...
December 12, 2018: Journal of the Air & Waste Management Association
Yuan Qin, Zhenping Qu, Cui Dong, Yan Wang, Na Huang
Rod-like, hexagonal and fiber-like SBA-15 mesoporous silicas were synthesized to support MnOx for toluene oxidation. This study showed that the morphology of the supports greatly influenced the catalytic activity in toluene oxidation. MnOx supported on rod-like SBA-15 (R-SBA-15) displayed the best catalytic activity and the conversion at 230°C reached more than 90%, which was higher than the other two catalysts. MnOx species consisted of coexisting MnO2 and Mn2 O3 on the three kinds of SBA-15 samples. Large amounts of Mn2 O3 species were formed on the surface and high oxygen mobility was obtained on MnOx supported on R-SBA-15, according to the H2 temperature programmed reduction (H2 -TPR) and X-ray photoelectron spectroscopy (XPS) results...
February 2019: Journal of Environmental Sciences (China)
Xingdong Qiu, Sugata P Tan, Morteza Dejam, Hertanto Adidharma
Various types of nanopores are encountered in many different engineering and science applications. Due to incomplete understanding of the phase behavior of fluids in nanosize confined space, the improvement of such applications has been largely based on experience and empirical approaches. Therefore, experimental studies on the phase behavior of confined fluids that are simple but accurate are still urgently needed. We recently developed a new isochoric procedure using a Differential Scanning Calorimeter (DSC) to measure the onset of vapor-liquid phase transitions, which has been successfully used in experiments measuring the vapor pressures of pure substances and the dew points of a bulk mixture in the absence of nanopores [Qiu et al...
December 5, 2018: Physical Chemistry Chemical Physics: PCCP
Pei Yuan, Xiaoling Li, Wangyang Wang, Haiyan Liu, Yan Yan, Haifeng Yang, Yuanyuan Yue, Xiaojun Bao
A series of SBA-15 with different modifications have been successfully prepared and applied as adsorbents to remove polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions. The morphology and structural properties of the chemically modified materials are all similar to pure SBA-15, and thus the difference of PAHs adsorption capacity can be directly attributed to the different functional groups, which is favorable to deeply explore the adsorption mechanism. Adsorption kinetics and isotherms experiments for naphthalene (Nap), anthracene (Ant) and pyrene (Pyr) were carried out and the results reveal that the adsorption processes follow a pseudo-second-order rate equation and the equilibrium can be achieved within 120 min for Nap and Ant while only 90 min for Pyr, indicating the more hydrophobic molecules, the easier and faster adsorption can be obtained...
November 29, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Joanna Dobrzyńska, Marzena Dąbrowska, Rafał Olchowski, Ryszard Dobrowolski
A gold(III)-imprinted thiocyanato-functionalized silica network of type SBA-15 was prepared by co-condensation of tetraethoxysilane (TEOS) with thiocyanatopropyltriethoxysilane (TCTES) in the presence of Pluronic123 and Au(III) ions. Compared to the non-imprinted material, the imprint has a higher selectivity and adsorption capacity for Au(III). The maximum static adsorption capacity for Au(III) is 475 mg·g-1 for the ion-imprinted, and 62 mg·g-1 for the non-imprinted sorbent. The imprint was applied to the sorption of Au(III) from digested geological samples prior to its determination by graphite furnace atomic absorption spectrometry...
November 28, 2018: Mikrochimica Acta
Xusheng Cheng, Dongxu Wang, Jiancong Liu, Xin Kang, Haijing Yan, Aiping Wu, Ying Gu, Chungui Tian, Honggang Fu
Decreasing Pd usage whilst maintaining a superior performance is promising, but remains a challenge in the catalytic field. Herein, we have demonstrated the highly efficient promotion of Mo2N with a reduced amount of Pd for the liquid-phase hydrogenation reaction. The Mo2N (2-3 nm) was uniformly anchored onto mesoporous SBA-15 by using PMo12 as the Mo source. The small size and good dispersion of Mo2N is favourable for allowing their effective contact with post-loading Pd. This good contact is conducive to developing a synergistic catalyst, which was verified by studying the liquid-phase hydrogenation of p-nitrophenol (PNP) to p-aminophenol (PAP) with NaBH4 as the H source...
November 23, 2018: Nanoscale
James Flynn, Sarah Mallen, Edel Durack, Paula M O'Connor, Sarah P Hudson
Mesoporous matrices of different pore size and chemical composition were explored as potential delivery matrices for the broad spectrum bacteriocin, nisin A. The adsorption of nisin A onto two mesoporous silicates (MPS - SBA-15, MCM-41) and two periodic mesoporous organosilanes (PMO - MSE, PMO-PA) was examined. It was found that hydrophobic interactions dominated in the adsorption of this peptide to the matrices, lending the highest adsorption to MCM-41 with a small pore size of 2.8 nm. The hydrophobic ethylene-bridged MSE (6 nm pore) improved the loading and protection of nisin A from degradation by a non-specific protease pepsin, over un-functionalised SBA-15 which had a slightly larger pore size and less hydrophobic moieties...
November 12, 2018: Journal of Colloid and Interface Science
Palle R Murthy, Parasuraman Selvam
Ordered mesoporous carbon (OMC) supported gold nanoparticles of size 3-4 nm having uniform dispersion were synthesized by sol-immobilization method. OMCs such as CMK-3 and NCCR-56 with high surface area and uniform pore size were obtained, respectively, using ordered mesoporous silicas such as SBA-15 and IITM-56 as hard templates, respectively. The resulting OMC supported monodispersed nano-gold, i. e., Au/CMK-3 and Au/NCCR-56, exhibited excellent performance as mild-oxidizing catalysts for oxidation of glycerol with high hydrothermal stability...
November 21, 2018: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Arash Yunessnia Lehi, Hamidreza Shagholani, Ali Nikpay, Mohsen Ghorbani, Mohammad Soleimani Lashkenari, Maryam Soltani
Clinical resistance to drugs and diminution in their side effects have become great issues for pharmacologists. In veterinary medicine, parasites like Trichomonas gallinae are of veterinary, hygienic and economic importance and can be treated by metronidazole. Unfortunately, scientific evidence has been reported about its resistance and serious side effects in trichomoniasis. In this research, it was attempted to introduce a new procedure to lower side effects of the drug molecules and also, enhance the treatment of disease...
November 15, 2018: International Journal of Pharmaceutics
V S Veena, Kavya Illath, Anish Lazar, C P Vinod, T G Ajithkumar, S Jayanthi
Solid state proton (1H) magic angle spinning (MAS) NMR has been employed to study the distribution of confined water in ethane substituted periodic mesoporous organosilicate (PMOE) materials. Proton spectra acquired at different hydration levels are analysed and interpreted in terms of water clusters of various sizes and distributions of water layers on the pore surface. For comparison, we also performed similar experiments on SBA-15. The formation of larger clusters at lower hydration suggests that the pores of PMOE are getting filled with water at lower hydration levels than those in SBA-15...
November 28, 2018: Physical Chemistry Chemical Physics: PCCP
M Carmen Ortega-Liebana, Jose L Hueso, Rodrigo Fernandez-Pacheco, Silvia Irusta, Jesus Santamaria
Herein we report on a novel inorganic peroxidase-mimicking nanocatalyst activated under blue LED photoirradiation. A novel flash-pyrolysis method has been developed for the generation of strong blue photoluminescence (PL) centers attributed to silicon and carbon-based sites within a mesoporous SBA-15 silica nanorod platform. The type of centers and their PL response can be controlled by varying the flash thermal treatment conditions. By tailoring the operating conditions the system can be driven towards the preferential generation of carbon-based luminescent centers, with or without the simultaneous generation of silicon-based centers...
October 28, 2018: Chemical Science
Zhifeng Xu, Peihong Deng, Junhua Li, Siping Tang, Ying Cui
In order to improve the diffusion kinetics of molecularly imprinted materials (MIMs), applying imprinting technology to mesoporous materials is a promising strategy. In the present study, an imprinting approach based on the combination of mesoporous silica materials and molecular imprinting technology is reported. Molecularly imprinted material (MIM) for 2,4-dichlorophenoxyacetic acid (2,4-D) was prepared by using 2,4-D as the template molecule, alkyne-modified β-cyclodextrin and propargyl amine as the combinatorial functional monomers and SBA-15 as the supporter...
January 1, 2019: Materials Science & Engineering. C, Materials for Biological Applications
Ana E Ferreira, M Rosário Ribeiro, Henri Cramail, João P Lourenço, Vicente Lorenzo, Ernesto Pérez, Maria L Cerrada
An approach to obtain disentangled ultra-high molecular weight polyethylene (UHMWPE) films is proposed using a common compression molding. For that, disentangled UHMWPE nascent powders from reactor are processed at temperatures lower than the main melting peak and at high pressure. Then, disentangled UHMWPE films obtained from homogeneous polymerization powders and from those that incorporate SBA-15 mesoporous silica can be easily achieved by this simple methodology. These disentangled UHMWPE based materials show very high crystallinity and, consequently, outstanding elastic modulus and hardness, both further increasing by presence of mesoporous SBA-15 in the hybrids...
September 25, 2018: Journal of the Mechanical Behavior of Biomedical Materials
Xun Liu, Yan-Li Gu, Bing-Bing Zhang, Qiu-Mei Dong, Yong-Le Li, Hui-Min Wang
The basic problems of the low dissolution rate of Tanshinone IIA (TSN) and the instability and precipitation of sodium tanshinone IIA sulfonate (STS) injection limit their usage in clinical. For these facts, the study aims to improve the dissolution rate of TSN and to enhance the sustained release effects of TSN and STS by using SBA-15 mesoporous molecular sieve as a drug carrier. Furthermore, controlling the pore size of SBA-15 and using different loaded methods to achieve expectations and provide a novel scheme for existing Danshen formulations...
February 1, 2019: Journal of Nanoscience and Nanotechnology
Shuo Wang, Zhiyu Wang, Yu Wang, Chunhui Xia, Enlv Hong, Liming Bai, Tao Li, Baiqi Wang
Nanosized TiO2 photocatalysis technology is one of the most promising technologies for the treatment of wastewater containing azo dyes. In this work, TiO2 was deposited on a mesoporous SBA-15 molecular sieve by chemical deposition, and rare earth (RE) metal neodymium (Nd) was further deposited on the surface of the catalyst to obtain an Nd-TiO2 -SBA-15 photocatalyst. The prepared photocatalyst was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and N2 adsorption-desorption...
October 17, 2018: Science of the Total Environment
András Sápi, Gyula Halasi, András Grósz, János Kiss, Albert Kéri, Gergőo Ballai, Gábor Galbács, Ákos Kukovecz, Zoltán Kónya
Controlled size Pt nanoparticles were anchored onto the surface of 3D mesoporous cobalt-oxide support and was tested in CO₂ hydrogenation reactions compared to commercial cobalt-oxide supported Pt nanoparticles prepared by the wet impregnation method as well as SBA-15 silica supported nanoparticles. Designed Pt/mesoporous cobalt-oxide catalysts showed the highest activity as well as the highest methane selectivity. Such catalyst was active at 573 K, while other catalysts showed activity >673 K.
January 1, 2019: Journal of Nanoscience and Nanotechnology
Luis Miguel Azofra, Natalia Morlanés, Albert Poater, Manoja K Samantaray, Balamurugan Vidjayacoumar, Khalid Albahily, Luigi Cavallo, Jean-Marie Basset
Very stable in operando and low-loaded atomic molybdenum on solid-support materials have been prepared and tested to be catalytically active for N2 -into-NH3 hydrogenation. Ammonia synthesis is reported at atmospheric pressure and 400 °C with NH3 rates of approximately 1.3×103  μmol h-1  gMo -1 using a well-defined Mo-hydride grafted on silica (SiO2-700 ). DFT modelling on the reaction mechanism suggests that N2 spontaneously binds on monopodal [(≡Si-O-)MoH3 ]. Based on calculations, the fourth hydrogenation step involving the release of the first NH3 molecule represents the rate-limiting step of the whole reaction...
October 11, 2018: Angewandte Chemie
Yogita Soni, I Kavya, T G Ajithkumar, C P Vinod
A modified deposition precipitation (DP) method has been developed to address a fundamental issue of supporting well dispersed Au nanoparticles on silica. Ammonium chloride (NH4Cl) plays an important role in in situ modifying the gold precursor (HAuCl4·3H2O) solution allowing facile deposition of gold NPs in the channels of SBA-15. The Au-SBA-15 catalyst (2.8 wt%) synthesized by this procedure showed 100% conversion for CO oxidation at room temperature with excellent stability at room temperature and high temperature...
October 30, 2018: Chemical Communications: Chem Comm
Qunfeng Yang, Nanzhengfang Jia, Chensi Shen, Jianqing Ma, Yuezhong Wen
Persulfates are recognized as promising oxidants and an alternative to Fenton reaction for water treatment. However, activation methods in hand restrict the practical application. Herein, we explore the possibility of Fe-N complexes being a catalyst for persulfate activation for the first time. The catalyst denoted as Fe-Im-SBA was synthesized from ferric chloride, imidazole, and SBA-15 at high temperature. The internal pore structure of Fe-Im-SBA was maintained well; Fe, N and C elements are evenly distributed on the catalyst...
December 2018: Environmental Science and Pollution Research International
Luhui Wang, Hui Liu, Han Ye, Rong Hu, Shuqing Yang, Guoli Tang, Kunqiang Li, Yanpeng Yang
Ni-CeO₂/SBA-15-V catalyst was prepared by the impregnation method with vacuum thermal treatment and used for CO₂ methanation reaction. Compared with Ni-CeO₂/SBA-15-air catalyst with thermal treatment in air, the reduced Ni-CeO₂/SBA-15-V catalyst with vacuum thermal treatment exhibited higher Ni dispersion and smaller Ni particle size. In CO₂ methanation reaction, the Ni-CeO₂/SBA-15-V catalyst was more active and selective than the Ni-CeO₂/SBA-15-air catalyst. The good activity and selectivity of Ni-CeO₂/SBA-15-V catalyst should be due to highly dispersed Ni in contact with small CeO₂ particles...
September 26, 2018: Nanomaterials
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