One-Step FSP Synthesis of Nanocrystalline Fe/Al2O3 and Fe-Ce/Al2O3 Catalyst for CO2 Hydrogenation Reaction

2018 ◽  
Vol 916 ◽  
pp. 134-138 ◽  
Author(s):  
Kanyarat Piriyasurawong ◽  
Sunthon Piticharoenphun ◽  
Okorn Mekasuwandumrong
Keyword(s):  
Catalytic Activity ◽  
Iron Oxide ◽  
Catalytic Performance ◽  
Hydrogenation Reaction ◽  
Flame Spray ◽  
One Step ◽  
Temperature Programmed ◽  
The One ◽  
Long Chain ◽  
Chain Hydrocarbon

Nanocrystalline Fe/Al2O3and Fe-Ce/Al2O3catalysts doped with various amounts of cerium were prepared using the one-step flame spray pyrolysis (FSP) technique. The characterization of the catalysts was measured by several methods such as X-ray diffraction, nitrogen physisorption and hydrogen temperature programmed reduction (H2-TPR) techniques. The results revealed that the FSP-made catalyst exhibited the characteristic pattern of FeAl2O4phase without any phases of aluminum or iron oxide. In addition, cerium (Ce) dopant did not alter crystal structure at low content. However, 7 wt% content of cerium dopant resulted in the formation of ceria (CeO) and iron oxide (Fe2O3) phase. The catalytic performance of the FSP-made catalyst was tested in carbon dioxide hydrogenation for selective production of long chain hydrocarbon, and was compared to conventional impregnation-made catalysts. In the comparison, the FSP-made catalyst exhibited lower catalytic activity but possessed a higher long chain hydrocarbon selectivity. After doping with Ce, the catalytic activity was improved while the hydrocarbon selectivity was decreased and shifted to the short chain hydrocarbon product. In the case of conventional-made catalysts, the activity remained unchanged but the hydrocarbon selectivity was decreased. Among all catalysts, the FSP-made Fe-Ce/Al2O3catalyst with 3% Ce-promoted catalyst exhibited the best performance in terms of selectivity to long chain hydrocarbon.

scholarly journals Rheological, Microstructural and Thermal Properties of Magnetic Poly(Ethylene Oxide)/Iron Oxide Nanocomposite Hydrogels Synthesized Using a One-Step Gamma-Irradiation Method

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1823
Author(s):  
Ivan Marić ◽  
Nataša Šijaković Vujičić ◽  
Anđela Pustak ◽  
Marijan Gotić ◽  
Goran Štefanić ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Ethylene Oxide ◽  
Molar Fraction ◽  
Magnetic Iron Oxide Nanoparticles ◽  
Γ Irradiation ◽  
Nanocomposite Hydrogels ◽  
One Step ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
The One

Magnetic polymer gels are a new promising class of nanocomposite gels. In this work, magnetic PEO/iron oxide nanocomposite hydrogels were synthesized using the one-step γ-irradiation method starting from poly(ethylene oxide) (PEO) and iron(III) precursor alkaline aqueous suspensions followed by simultaneous crosslinking of PEO chains and reduction of Fe(III) precursor. γ-irradiation dose and concentrations of Fe3+, 2-propanol and PEO in the initial suspensions were varied and optimized. With 2-propanol and at high doses magnetic gels with embedded magnetite nanoparticles were obtained, as confirmed by XRD, SEM and Mössbauer spectrometry. The quantitative determination of γ-irradiation generated Fe2+ was performed using the 1,10-phenanthroline method. The maximal Fe2+ molar fraction of 0.55 was achieved at 300 kGy, pH = 12 and initial 5% of Fe3+. The DSC and rheological measurements confirmed the formation of a well-structured network. The thermal and rheological properties of gels depended on the dose, PEO concentration and initial Fe3+ content (amount of nanoparticles synthesized inside gels). More amorphous and stronger gels were formed at higher dose and higher nanoparticle content. The properties of synthesized gels were determined by the presence of magnetic iron oxide nanoparticles, which acted as reinforcing agents and additional crosslinkers of PEO chains thus facilitating the one-step gel formation.

Oxygen Radicals Occlusion/Release Behavior of Nanoporous Aluminosilicate, Ca12Al14-XSiXO33+0.5X (0≦X≦4)

2006 ◽  
Vol 45 ◽  
pp. 2105-2109
Author(s):  
Makoto Nagashima ◽  
Daisuke Hirabayashi ◽  
Kenzi Suzuki
Keyword(s):  
Catalytic Activity ◽  
Oxygen Content ◽  
Oxygen Radicals ◽  
Catalytic Performance ◽  
Oxygen Release ◽  
Release Behavior ◽  
Temperature Programmed Reduction ◽  
Temperature Programmed Oxidation ◽  
Temperature Range ◽  
Temperature Programmed

Oxygen radicals occlusion / release behavior of nanoporous aluminosilicate, Ca12Al14-XSiXO33+0.5X (0≦X≦4), synthesized under different condition was examined by the temperature programmed reduction (TPR) in an atmosphere of hydrogen in the temperature range of 200-1000°C and temperature programmed oxidation (TPO) measurement at 800°C. From the TPR results of Ca12Al14O33 (X=0) and Ca12Al10Si4O35 (X=4), it was found that there were three oxygen release peaks, denoted as α, β and γ, on each sample and the peaks appeared in the temperature range 300-420°C, 420-600°C, and 600-750°C, respectively. The oxygen contents of α and γ of samples were almost the same. However, the oxygen content of β in the sample with x = 4 was much larger, almost double, compared to that in x = 0. From the TPR, TPO results and catalytic performance, it was concluded that the oxygen content of β peak strongly influenced the catalytic activity of the nanoporous aluminosilicate in the propylene combustion.

One-Step Synthesis of Nano-Size Iron Oxide /Three-Dimensional Wormlike Hierarchical Mesoporous SiO2 Catalysts and its Catalytic Performance on Phenol Hydroxylation

2013 ◽  
Vol 662 ◽  
pp. 202-206
Author(s):  
Jia Feng Wu ◽  
Yu Mei Zhao ◽  
Peng Liang
Keyword(s):  
Iron Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Catalytic Performance ◽  
Phenol Hydroxylation ◽  
Weight Percentage ◽  
One Step ◽  
Hierarchical Pore ◽  
Nano Size

A series of nano-sized iron oxide supported on 3D wormlike hierarchical mesoporous SiO2 catalysts were synthesized by one-step hydrothermal synthesis. The samples were characterized by XRD, N2 sorption, FT-IR, UV–Vis, TEM and ICP-AES. The catalysts were probed for the oxidation of phenol employing hydrogen peroxide. The results indicate that the materials exhibit high surface area and 3D wormlike hierarchical pore, iron ions exist as isolated framework species when the weight percentage content of iron is below 0.24 and nano-size iron oxide is dispersed in the surface (iron content above 0.24 wt%). Catalytic performance indicates that nano-size iron oxide supported on SiO2 is useful to enhance both the catalytic activity and the selectivity of target products compared with isolated iron species.

Carbon Dioxide Hydrogenation to Methanol over Cu/ZnO-SBA-15 Catalyst: Effect of Metal Loading

2017 ◽  
Vol 380 ◽  
pp. 151-160 ◽  
Author(s):  
Sara Faiz Hanna Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Maizatul Shima Shaharun ◽  
Duvvria Subbarao ◽  
Ahmed Elbagir
Keyword(s):  
Catalytic Activity ◽  
Carbon Source ◽  
Active Sites ◽  
Low Cost ◽  
Fixed Bed ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Hydrogenation Reaction ◽  
Supported Metal Catalysts ◽  
Metal Loading

Utilization of CO2 as a carbon source to produce valuable chemicals is one of the important ways to reduce the global warming caused by increasing CO2 in the atmosphere. Supported metal catalysts are crucial to produce clean and renewable fuels and chemicals from the stable CO2 molecules. The catalytic conversion of CO2 into methanol is recently under increased scrutiny as an opportunity to be used as a low-cost carbon source. Therefore, a series of the bimetallic Cu/ZnO-based catalyst supported by SBA-15 were synthesized via an impregnation technique with different total metal loading and tested in the catalytic hydrogenation of CO2 to methanol. The morphological and textural properties of the synthesized catalysts were determined by transmission electron microscopy (TEM), temperature programmed desorption, reduction, oxidation and pulse chemisorption (TPDRO), and N2-adsorption. The CO2 hydrogenation reaction was performed in a microactivity fixed-bed system at 250oC, 2.25 MPa, and H2/CO2 ratio of 3. Experimental results showed that the catalytic structure and performance were strongly affected by the loading of the active site. Where, the catalytic activity, the methanol selectivity as well as the space-time yield increased with increasing the metal loading until it reaches the maximum values at a metal loading of 15 wt% while further addition of metal inhibits the catalytic performance. The higher catalytic activity of 14% and methanol selectivity of 92% was obtained over a Cu/ZnO-SBA-15 catalyst with a total bimetallic loading of 15 wt%. The excellent performance of 15 wt% Cu/ZnO-SBA-15 catalyst is attributed to the presence of well dispersed active sites with small particle size, higher Cu surface area, and lower catalytic reducibility.

Recoverable Microparticle-Supported Metal Nanocatalysts

2019 ◽  
Author(s):  
Arthur Bonfá Fernandes ◽  
Mariia V. Pavliuk ◽  
Cristina Paun ◽  
Alexandrina C. Carvalho ◽  
Cassiana S. Nomura ◽  
...  
Keyword(s):  
Catalytic Properties ◽  
Metal Oxide Nanoparticles ◽  
Catalytic Performance ◽  
Chemical Transformations ◽  
Flow Conditions ◽  
Facile Synthesis ◽  
Mild Conditions ◽  
One Step ◽  
The One ◽  
Supported Metal

Metal nanoparticles have been widely exploited in catalysis, but their full impact on the environment and human health is still under debate. Here we describe the one-step fabrication of polymer microbead-supported metal and metal oxide nanoparticles and their application as recoverable nanocatalysts for reactions under batch and flow conditions. Au, Ag and Fe<sub>3</sub>O<sub>4</sub> nanoparticles were prepared directly at the surface of benzylamine-coated spherical polymer beads in water by using low energy microwave radiation. The morphology and size of the nanoparticles, and therefore their catalytic properties, were tuned by modifying the bead surface using betalamic acid, an antioxidant from plant origin. The catalytic performance and recovery of these environmentally friendly nanocatalysts was demonstrated towards model redox chemical transformations. We anticipate the results reported herein can provide important insights into the controlled and facile synthesis of microparticle supported nanocatalysts under mild conditions.

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

The one-step synthesis and surface functionalization of dumbbell-like gold–iron oxide nanoparticles: a chitosan-based nanotheranostic system

2016 ◽  
Vol 52 (2) ◽  
pp. 378-381 ◽  
Author(s):  
Nina Kostevsek ◽  
Erica Locatelli ◽  
Chiara Garrovo ◽  
Francesca Arena ◽  
Ilaria Monaco ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Surface Functionalization ◽  
Oxide Nanoparticles ◽  
Therapeutic Tool ◽  
Chitosan Matrix ◽  
System P ◽  
One Step ◽  
The One

The first one-step synthesis of dumbbell-like gold–iron oxide nanoparticles has been reported here. Surface functionalization with a biocompatible chitosan matrix allowed us to obtain a novel targetable diagnostic and therapeutic tool.

scholarly journals Enhanced CO2 Methanation Reaction in C1 Chemistry over a Highly Dispersed Nickel Nanocatalyst Prepared Using the One-Step Melt-Infiltration Method

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 643 ◽  
Author(s):  
Eui Hyun Cho ◽  
Woohyun Kim ◽  
Chang Hyun Ko ◽  
Wang Lai Yoon
Keyword(s):  
Catalytic Performance ◽  
High Dispersion ◽  
Co2 Conversion ◽  
Co2 Methanation ◽  
Gas Treatment ◽  
Ni Content ◽  
Melt Infiltration ◽  
One Step ◽  
The One ◽  
Infiltration Method

The Paris Agreement requires the world to put the best efforts to reduce CO2 emissions, due to the global warming problems. As a promising technology corresponding to this greenhouse gas treatment, the CO2 methanation process a.k.a power to gas (PtoG), which catalytically converts CO2 into methane, has been in the limelight. To develop an efficient catalytic process, it is necessary to design a low-cost and high-efficiency catalyst for high CO2 conversion and CH4 selectivity. In this study, we have developed Ni/γ-Al2O3 catalysts by the one-step melt-infiltration method, where both aging and calcination are done in one pot. For enhancement of the catalytic activity and selectivity, sufficient Ni content (>25 wt %) and a high dispersion (<10 nm) are simultaneously required. Thus, the aging conditions of the melt-infiltration methods, e.g., time and temperature, were optimized for the high dispersion with sufficient Ni content (15–50 wt %). The catalytic performance tests were carried out under atmospheric pressure, 275 to 400 °C and gas hourly velocity (GHSV) = 25,000 h−1. And the various characteristic analyses (Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), H2-chemisorption, temperature programmed reduction (TPR), etc.) were performed to confirm the effects on the catalytic performance. As a result, based on the experiments and the characterization data, the 30 wt %-Ni catalyst (Ni particles size = 11 nm) showed the best CO2 conversion at 300 °C and the 20 wt % one having the highest Ni dispersion (Ni particles size = 8.8 nm), which showed the best intrinsic reaction rate and CH4 selectivity in the entire temperature range.

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