scholarly journals Synthesis, Characterization and Catalytical Effects of Fe Contents on Pyrolysis of Cellulose with Fe2O3/SBA-15 Catalysts

2020 ◽  
Vol 24 (2) ◽  
pp. 92-102
Author(s):  
Agija Stanke ◽  
Valdis Kampars ◽  
Kristine Lazdovica
Keyword(s):  
Xrd Analysis ◽  
Hydroxyl Group ◽  
Iron Loading ◽  
Pyrolysis Products ◽  
Catalytic Selectivity ◽  
Pluronic P123 ◽  
Silica Source ◽  
Acidic Conditions ◽  
Post Synthesis ◽  
Adsorption Desorption

AbstractIn this study mesoporous SBA-15 was synthesized under acidic conditions using triblock copolymer Pluronic P123 as template and tetraethyl orthosilicate as a silica source. SBA-15 was modified by different iron loading (1.8 %, 5 % and 10 %) via post-synthesis impregnation with Fe(NO3)3·9H2O. The obtained catalysts were characterized using XRD analysis, WDXRF spectroscopy and N2 adsorption-desorption analysis. Pyrolysis of cellulose with and without the catalyst was investigated using TG-FTIR. It was found that the presence of the synthesized catalysts affects formation of solid residue and significantly alters the composition of the other pyrolysis products. All catalysts considerably reduced the fraction of compounds containing hydroxyl group. Fe (10 %)/SBA-15 exhibited the highest deoxygenation ability. SBA-15 showed the highest catalytic selectivity for synthesis of olefins, while Fe (1.8 %)/SBA-15 showed the highest catalytic selectivity for synthesis of aromatic hydrocarbons.

Preparation and Characterization of Fe2O3/ SBA-15 for Fischer-Tropsch Process

2020 ◽  
Vol 850 ◽  
pp. 144-150
Author(s):  
Agija Stanke ◽  
Valdis Kampars ◽  
Oana A. Lazar ◽  
Marius Enachescu
Keyword(s):  
Average Pore Size ◽  
Direct Synthesis ◽  
Synthesis Method ◽  
Xrd Analysis ◽  
Hexagonal Structure ◽  
Catalyst Characterization ◽  
Average Pore ◽  
Pluronic P123 ◽  
Silica Source ◽  
Adsorption Desorption

In this study Fe2O3/SBA-15 catalyst was synthesized via direct synthesis method under acidic conditions using triblock copolymer Pluronic P123 as template, tetraethyl orthosilicate as a silica source and Fe (NO3)3∙9H2O as iron source. Template was removed using extraction and calcination. The obtained catalyst was characterized using XRD analysis, WDXRF spectroscopy, N2 adsorption-desorption analysis and STEM–EDX measurements. Results of catalyst characterization showed that the synthesized Fe2O3/SBA-15 is mesoporous silica with 2D p6mm hexagonal mesostructure loaded with 15.6 wt.% Fe2O3. Average pore size was 6.95 nm, homogeneous immobilized Fe2O3 nanoparticles do not disrupt the porous hexagonal structure of the support.

scholarly journals Effects of Al and Co Promoters on CuO/SBA-15/Kaolinite Catalyst Properties and CO2 Hydrogenation at Low Pressure

2021 ◽  
Vol 259 ◽  
pp. 04001
Author(s):  
Zane Abelniece ◽  
Valdis Kampars ◽  
Helle-Mai Piirsoo ◽  
Aile Tamm
Keyword(s):  
Fixed Bed ◽  
Mesoporous Structure ◽  
Xrd Analysis ◽  
Hydrogenation Reaction ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Kaolinite Clay ◽  
Post Synthesis ◽  
Adsorption Desorption ◽  
Hydrogenation Of Co

CuO on mesoporous silica catalyst was prepared with post synthesis impregnation method, and the effects of Al and Co promoters on CuO/SBA-15/kaolinite catalyst properties and CO2 hydrogenation were studied. The mixing technology with kaolinite clay (containing Al2O3) was used to obtain the granules and to enhance the CO2 conversion to methanol as a product. The performance of all catalysts for catalytic hydrogenation of CO2 was evaluated on a fixed-bed tubular micro-activity reactor at 20 bar and 250°C with H2/CO2 molar ratio 3:1. XRD analysis, N2 adsorption-desorption analysis and SEM-EDX analysis indicated that the mesoporous structure of SBA-15 remains after loading with CuO and promoters, and after mixing with kaolinite clay. Results were compared with results obtained with commercial CuO/Al2O3 catalyst, which showed high MeOH selectivity (78%) during CO2 hydrogenation reaction.

scholarly journals Infrared Spectroscopic and Scanning Electron Microscopy Study of Ibuprofen Loading onto the Molecular Sieve Mesoporous Silica SBA-15 Material

2018 ◽  
Vol 34 (5) ◽  
pp. 2631-2636
Author(s):  
Maria Ulfa ◽  
Didik Prasetyoko
Keyword(s):  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Hydroxyl Group ◽  
Structure Directing Agent ◽  
Sem Image ◽  
Pluronic P123 ◽  
Silica Source ◽  
Result Show ◽  
Molecule Model ◽  
The Given

The SBA-15 was studied for the first time for ibuprofen loading as anti inflamantory molecule model. The SBA-15 was synthesized from Pluronic P123 as the structure-directing agent and TEOS as the silica source. The framework capacity and structural change of the SBA-15 was investigated by varying the amount loading of ibuprofen inflamantory molecule. The structural properties of the synthesized samples after laoding treatment was analyzed by FTIR, SEM and EDX. The decreasing intensity of the SBA-15 as increasing ibuprofen loading by FTIR measurement demonstrated that a big part of mesoporous pipe has been covered by ibuprofen molecule. Spectra of FTIR also show that increasing ibuprofen molecule was decrease the number of sylanol group of the SBA-15 but increase carbonyl and hydroxyl group. The SEM image show not only the average widht of the micropencil-like structure of SBA-15 close to the (1-2 mµ) and lenght of pipe close to the (30 mµ) but also white coral-like structure from ibuprofen excess. The ibuprofen molecule in ona part were obtained homogeneously dispersed within the pore structure of the SBA-15 but in the other part agglomerated without unformity. The elemental analysis by EDAX showed that the sample containing silica, oxygen,carbon and hydrogen that changed gradually as varying ibuprofen loadig. The result show that the structure of SBA-15 has been stable at the given condition which is afforded a maximum loading ibuprofen up to 10 mol at room temperature. The slow release of ibuprofen/SBA-15 is ascribed to its unique SBA-15 structure which is achieved optimum release up to 67% within 60 min.

scholarly journals Preparation and characterization of corn starch/PVA/glycerol composite films incorporated with ε-polylysine as a novel antimicrobial packaging material

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Gao Yurong ◽  
Li Dapeng
Keyword(s):  
Water Solubility ◽  
Corn Starch ◽  
Composite Films ◽  
Antimicrobial Properties ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Packaging Material ◽  
Hydroxyl Group ◽  
Electron Microscopic ◽  
Antimicrobial Packaging

AbstractCorn starch/polyvinyl alcohol (PVA)/glycerol composite films incorporated with ε-polylysine were prepared, and their properties were investigated. The Fourier-transform infrared (FTIR) spectroscopy indicated that the interactions happened between the amino group of ε-polylysine and hydroxyl group starch/PVA composite films. X-ray diffraction (XRD) analysis showed that the addition of ε-polylysine decreased the intensity of all crystal peaks. Thermogravimetric (TGA) analysis suggested that ε-polylysine improved the thermal stability of composite films. Scanning electron microscopic (SEM) analysis showed that the upper surface of composite films incorporated with ε-polylysine presented more compact and flat surface. The antimicrobial activity of the composite film progressively increased with the increasing of ε-polylysine concentration (P < 0.05). The tensile strength, elongation at break and water absorption significantly increased, whereas water solubility decreased with the increasing of ε-polylysine concentration (P < 0.05). Therefore, the corn starch/PVA/glycerol composite films incorporated with ε-polylysine had good mechanical, physical and antimicrobial properties and could have potential application as a novel antimicrobial packaging material.

scholarly journals Application of microwave radiation in the grafting of acidic sites on SBA-15 type material

2021 ◽  
Author(s):  
Maciej Trejda ◽  
Magdalena Drobnik ◽  
Ardian Nurwita
Keyword(s):  
Microwave Radiation ◽  
Thermal Analyses ◽  
Conventional Heating ◽  
Material Surface ◽  
Test Reaction ◽  
Study Materials ◽  
Mesoporous Support ◽  
Acidic Sites ◽  
Post Synthesis ◽  
Adsorption Desorption

AbstractMesoporous silica of SBA-15 type was modified for the first time with 3-(trihydroxysiyl)-1-propanesulfonic acid (TPS) by post-synthesis modification involving microwave or conventional heating in order to generate the Brønsted acidic centers on the material surface. The samples structure and composition were examined by low temperature N2 adsorption/desorption, XRD, HRTEM, elemental and thermal analyses. The surface properties were evaluated by esterification of acetic acid with n-hexanol used as the test reaction. A much higher efficiency of TPS species incorporation was reached with the application of microwave radiation for 1 h than conventional modification for 24 h. It was found that the structure of mesoporous support was preserved after modification using both methods applied in this study. Materials obtained with the use of microwave radiation showed a superior catalytic activity and high stability.

scholarly journals Facile Preparation of Mesoporous MCM-48 Containing Silver Nanoparticles with Fly Ash as Raw Materials for CO Catalytic Oxidation

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 841
Author(s):  
Dong Tian ◽  
Yonghong Chen ◽  
Xiaoyong Lu ◽  
Yihan Ling ◽  
Bin Lin
Keyword(s):  
Silver Nanoparticles ◽  
Fly Ash ◽  
Co Oxidation ◽  
Surface Composition ◽  
Raw Materials ◽  
Silica Source ◽  
Co Conversion ◽  
Co Catalytic Oxidation ◽  
Adsorption Desorption

An environmentally friendly method was proposed to prepare mesoporous Mobil Composition of Matter No.48 (MCM-48) using fly ash as the silica source. Silver nanoparticles were infiltrated on MCM-48 facilely by an in situ post-reduction method and evaluated as an effective catalyst for CO oxidation. The as-prepared MCM-48 and Ag/MCM-48 nanoparticles were characterized by XRD, N2 adsorption/desorption, and TEM. Investigations by means of XPS for Ag/MCM-48 were performed in order to illuminate the surface composition of the samples. Studies revealed the strong influence of the loading of Ag nanoparticles on catalysts in the oxidation of CO. CO conversion values for Ag/MCM-48 of 10% and 100% were achieved at temperatures of 220 °C and 270 °C, respectively, indicating that the Ag-decorated MCM-48 catalyst is extremely active for CO oxidation.

scholarly journals Pyrolysis Products Distribution of Enzymatic Hydrolysis Lignin with/without Steam Explosion Treatment by Py-GC/MS

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 187
Author(s):  
Yuguo Dong ◽  
Xinyu Lu ◽  
Chengjuan Hu ◽  
Liang Li ◽  
Qixiang Hu ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Steam Explosion ◽  
Pyrolysis Product ◽  
Product Distribution ◽  
Hydroxyl Group ◽  
Hydrolysis Lignin ◽  
Pyrolysis Gas ◽  
Pyrolysis Products ◽  
Structural Framework ◽  
Main Component

This paper investigated the pyrolytic behaviors of enzymatic hydrolysis lignin (EHL) and EHL treated with steam explosion (EHL-SE) by pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS). It was shown that the main component of the pyrolysis products was phenolic compounds, including G-type, H-type, S-type, and C-type phenols. With different treatment methods, the proportion of units in phenolic products had changed significantly. Meanwhile, proximate, elemental, and FTIR analysis of both lignin substrates were also carried out for a further understanding of the lignin structure and composition with or without steam explosion treatment. FTIR result showed that, after steam explosion treatment, the fundamental structural framework of the lignin substrate was almost unchangeable, but the content of lignin constituent units, e.g., hydroxyl group and alkyl group, evidently changed. It was noticeable that 2-methoxy-4-vinylphenol with 11% relative content was the most predominant pyrolytic product for lignin after steam explosion treatment. Combined with the above analysis, the structural change and pyrolysis product distribution of EHL with or without steam explosion treatment could be better understood, providing more support for the multi-functional utilization of lignin.

Rapid Synthesis of MCM-41 from Rice Husk Using Ultrasonic Wave: Optimation of Sonication Time

2019 ◽  
Vol 948 ◽  
pp. 198-205
Author(s):  
Suyanta Suyanta ◽  
Eko Sri Kunarti ◽  
Bambang Rusdiarso ◽  
Dritta Anies Cahaya ◽  
Efa Radnawati ◽  
...  
Keyword(s):  
Optimum Condition ◽  
Ultrasonic Wave ◽  
Rice Husk ◽  
Nitrogen Adsorption ◽  
Sonication Time ◽  
Ultrasound Waves ◽  
Comb Structure ◽  
Silica Source ◽  
Adsorption Desorption ◽  
Mcm 41

Ultrasound waves with 48 KHz of frequency were applied for the synthesis of MCM-41 using rice husk as the silica source. The effect of sonication time (30, 60, 90, 120, 150, 180, and 210 min) on the crystallinity of calcined MCM-41 was investigated. Characterization using XRD and FTIR indicated that the ordered structure of MCM-41 could be synthesized by ultrasonic wave. Sonication time at 150 min was found to be the optimum condition. The nitrogen adsorption-desorption isotherms informed that the mesoporous material produced at the optimum condition has 794.73 m2·g-1of surface area, 3.02 nm of BJH pore diameter, 1.17 nm of wall thickness, and 0.68 ml·g-1 of pore volume. While based on the TEM image, the material has hexagonal or a honey-comb structure.

scholarly journals Adsorption of As(V) from Aqueous Solution on Chitosan-Modified Diatomite

2020 ◽  
Vol 17 (2) ◽  
pp. 429 ◽  
Author(s):  
Qintao Yang ◽  
Liang Gong ◽  
Lili Huang ◽  
Qinglin Xie ◽  
Yijian Zhong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Ph Effect ◽  
Freundlich Isotherm ◽  
Xrd Analysis ◽  
Optimal Value ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Modified Diatomite

A novel chitosan (CS)-modified diatomite (Dt) was prepared by a simple mixture in the mass ratio to remove As(V) from aqueous solution in this research. The CS-modified Dt adsorbent was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD) analysis. The parameters to influence the adsorption of As(V) ion were studied under such conditions as kinetics, adsorption isotherm, and pH effect. The results revealed that adsorption of As(V) was initially rapid and the equilibrium time was reached after 40 min. The optimal value of the pH was 5.0 for better adsorption. The equilibrium data were well fitted to the Langmuir isotherm compared to the Freundlich isotherm, and exhibited the highest capacity and removal efficiency of 94.3% under an initial As(V) concentration of 5 mg/L. The kinetic data were well described by the pseudo-second-order model. In addition, 0.1 M NaOH has the best desorption efficiency of As(V) adsorbed on CS-modified Dt, and the removal efficiency of As(V) was still higher than 90% when after six adsorption-desorption cycles. These results showed that the CS-modified Dt could be considered as a potential adsorbent for the removal of As(V) in aqueous solution.

scholarly journals Effects of Sintering Temperature Variation on Synthesis of Glass-Ceramic Phosphor Using Rice Husk Ash as Silica Source

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5413
Author(s):  
Rabiatul Adawiyah Abdul Wahab ◽  
Mohd Hafiz Mohd Zaid ◽  
Sidek Hj. Ab Aziz ◽  
Khamirul Amin Matori ◽  
Yap Wing Fen ◽  
...  
Keyword(s):  
Rice Husk ◽  
Glass Ceramic ◽  
Rice Husk Ash ◽  
Glass Ceramics ◽  
Xrd Analysis ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Silica Source ◽  
Quenching Method

In this study, the authors attempted to propose the very first study on fabrication and characterization of zinc-boro-silicate (ZBS) glass-ceramics derived from the ternary zinc-boro-silicate (ZnO)0.65(B2O3)0.15(RHA)0.2 glass system through a conventional melt-quenching method by incorporating rice husk ash (RHA) as the silica (SiO2) source, followed by a sintering process. Optimization of sintering condition has densified the sintered samples while embedded beta willemite (β-Zn2SiO4) and alpha willemite (α-Zn2SiO4) were proven in X-ray diffraction (XRD) analysis. Field emission scanning electron microscopy (FESEM) has shown the distribution of willemite crystals in rhombohedral shape crystals and successfully form closely-packed grains due to intense crystallization. The photoluminescence (PL) spectra of all sintered ZBS glasses presented various emission peaks at 425, 463, 487, 531, and 643 nm corresponded to violet, blue, green, and red emission, respectively. The correlation between the densification, phase transformation, microstructure, and photoluminescence of Zn2SiO4 glass-ceramic phosphor is discussed in detail.

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