scholarly journals Obtenção de catalisador nanoestruturado utilizando óxido de ferro suportado em resíduo de cerâmica vermelha

2019 ◽  
Vol 40 ◽  
pp. 94
Author(s):  
Fabiele Schaefer Rodrigues ◽  
Marcela Trojahn Nunes ◽  
Jocenir Boita
Keyword(s):  
Catalytic Activity ◽  
Iron Oxide ◽  
Hydrothermal Method ◽  
Scientific Community ◽  
National Laboratory ◽  
High Catalytic Activity ◽  
Nanostructured Catalyst ◽  
Synchrotron Light ◽  
Object Of Study ◽  
Technological Interest

The use of nanoparticles in the field of catalysis has been the object of study by the scientific community, due to the high catalytic activity that the nanoparticles have in front of some reactions of technological interest. The objective of this work is to obtain a nanostructured catalyst using iron oxide supported on red ceramic residue (RCV), through nanostructures synthesized by the hydrothermal method, measured through the absorption of lightning in the XANES region through the National Laboratory of Synchrotron Light LNLS).

Efficient visible-light-induced hydrogen evolution from water splitting using a nanocrystalline nickel phosphide catalyst

RSC Advances ◽  
2016 ◽  
Vol 6 (29) ◽  
pp. 24361-24365 ◽  
Author(s):  
Weiming Wu ◽  
Xianyang Yue ◽  
Xiao-Yuan Wu ◽  
Can-Zhong Lu
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Hydrothermal Method ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Visible Light Irradiation ◽  
Light Irradiation ◽  
Good Stability ◽  
High Catalytic Activity ◽  
Nickel Phosphide

Nanocrystalline Ni12P5 was synthesized by a simple hydrothermal method. It showed high catalytic activity (10 760 μmol h−1 g−1, TOF = 9.3 h−1) and good stability (15 h) for the hydrogen evolution from water under visible light irradiation.

scholarly journals Hybrid Catalysts for CO2 Conversion into Cyclic Carbonates

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 325 ◽  
Author(s):  
Carla Calabrese ◽  
Francesco Giacalone ◽  
Carmela Aprile
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Scientific Community ◽  
Heterogeneous Catalysts ◽  
Metal Organic Framework ◽  
High Catalytic Activity ◽  
Co2 Conversion ◽  
Cyclic Carbonates ◽  
Hybrid Catalysts ◽  
Metal Organic

The conversion of carbon dioxide into valuable chemicals such as cyclic carbonates is an appealing topic for the scientific community due to the possibility of valorizing waste into an inexpensive, available, nontoxic, and renewable carbon feedstock. In this regard, last-generation heterogeneous catalysts are of great interest owing to their high catalytic activity, robustness, and easy recovery and recycling. In the present review, recent advances on CO2 cycloaddition to epoxide mediated by hybrid catalysts through organometallic or organo-catalytic species supported onto silica-, nanocarbon-, and metal–organic framework (MOF)-based heterogeneous materials, are highlighted and discussed.

scholarly journals Design of Polymer-Embedded Heterogeneous Fenton Catalysts for the Conversion of Organic Trace Compounds

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 942
Author(s):  
Christoph Horn ◽  
Stephanie Ihmann ◽  
Felix Müller ◽  
Doris Pospiech ◽  
Konstantin B. L. Borchert ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Iron Oxide ◽  
High Catalytic Activity ◽  
Reactive Black 5 ◽  
Heterogeneous Fenton ◽  
Iron Leaching ◽  
Trace Compounds ◽  
Organic Trace Compounds ◽  
Organic Trace ◽  
Supported Iron

Advanced oxidation processes are the main way to remove persistent organic trace compounds from water. For these processes, heterogeneous Fenton catalysts with low iron leaching and high catalytic activity are required. Here, the preparation of such catalysts consisting of silica-supported iron oxide (Fe2O3/SiOx) embedded in thermoplastic polymers is presented. The iron oxide catalysts are prepared by a facile sol–gel procedure followed by thermal annealing (calcination). These materials are mixed in a melt compounding process with modified polypropylenes to stabilize the Fe2O3 catalytic centers and to further reduce the iron leaching. The catalytic activity of the composites is analyzed by means of the Reactive Black 5 (RB5) assay, as well as by the conversion of phenol which is used as an example of an organic trace compound. It is demonstrated that embedding of silica-supported iron oxide in modified polypropylene turns the reaction order from pseudo-first order (found for Fe2O3/SiOx catalysts), which represents a mainly homogeneous Fenton reaction, to pseudo-zeroth order in the polymer composites, indicating a mainly heterogeneous, surface-diffusion-controlled process.

scholarly journals Magnetic Nanoparticles for Photocatalytic Ozonation of Organic Pollutants

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 703 ◽  
Author(s):  
Carla A. Orge ◽  
O. Salomé G. P. Soares ◽  
Patrícia S. F. Ramalho ◽  
M. Fernando R. Pereira ◽  
Joaquim L. Faria
Keyword(s):  
Photocatalytic Activity ◽  
Catalytic Activity ◽  
Iron Oxide ◽  
Magnetic Nanoparticles ◽  
Chemical Vapour ◽  
Synthesis Process ◽  
High Catalytic Activity ◽  
Carbon Phase ◽  
Industrial Pollutants ◽  
Photocatalytic Ozonation

Magnetic nanoparticles (MNP) composed of iron oxide (or other metal–FeO cores) coated with carbon produced by chemical vapour decomposition (CVD) were used in the photocatalytic ozonation of oxamic acid (OMA) which we selected as a model pollutant. The incorporation of Ag and Cu on FeO enhanced the efficiency of the process. The carbon phase significantly increased the photocatalytic activity towards the conversion of OMA. As for the synthesis process, raising the temperature of CVD improved the performance of the produced photocatalysts. The obtained results suggested that the carbon phase is directly related to high catalytic activity. The most active photocatalyst (C@FeO_CVD850) was used in the removal of other compounds (dyes, industrial pollutants and herbicides) from water and high mineralization levels were attained. This material was also revealed to be stable during reutilisation.

Effects of Diameters on the Catalytic Activity of Spherical V-MCM-41 in the Selective Oxidation of Styrene

2012 ◽  
Vol 549 ◽  
pp. 137-140
Author(s):  
Yu Chen ◽  
Hua Qin ◽  
Xiao Bo Shi ◽  
Yan Kong
Keyword(s):  
Catalytic Activity ◽  
Hydrothermal Method ◽  
Selective Oxidation ◽  
Heterogeneous Catalysts ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Precise Control ◽  
Mcm 41

Spherical V-MCM-41s with different diameter are synthesized by direct hydrothermal method through the precise control over the molar ratio of NaOH/TEOS. Vanadium supported on spherical MCM-41s is also prepared by impregnation methods. They are used as heterogeneous catalysts for the oxidation of styrene with H2O2 as oxidant. The results suggest that all catalysts have high catalytic activity, which increases with their diameter decreasing.

Hollow anatase TiO2 nanoparticles with excellent catalytic activity for dichloromethane combustion

RSC Advances ◽  
2016 ◽  
Vol 6 (66) ◽  
pp. 61610-61614 ◽  
Author(s):  
Haifeng Huang ◽  
Xixiong Zhang ◽  
Xiaojia Jiang ◽  
Kang Dou ◽  
Zhiyi Ni ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Tio2 Nanoparticles ◽  
Hydrothermal Method ◽  
Anatase Tio2 ◽  
High Catalytic Activity

Hollow anatase TiO2 nanoparticles around 11.4 nm in size were prepared by a CTAB-assisted hydrothermal method. The catalyst showed high catalytic activity for dichloromethane (DCM) combustion with 90% DCM conversion at 201 °C.

Morphology effect of one-dimensional iron oxide nanocatalysts on Fischer–Tropsch synthesis

2016 ◽  
Vol 6 (20) ◽  
pp. 7505-7511 ◽  
Author(s):  
Jiaqiang Sun ◽  
Yilong Chen ◽  
Jiangang Chen
Keyword(s):  
Catalytic Activity ◽  
Iron Oxide ◽  
Hydrothermal Method ◽  
Tropsch Synthesis ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
One Dimensional ◽  
One Step ◽  
Morphology Effect

One-dimensional iron oxide nanocatalysts have been fabricated by a one-step hydrothermal method and show distinguished catalytic activity and selectivity.

COBALT OXIDE DECORATED FLOWER-LIKE g-C3N4 HYBRID NANOMATERIALS FOR CARBON MONOXIDE OXIDATION

2016 ◽  
Vol 24 (05) ◽  
pp. 1750058 ◽  
Author(s):  
YAN WANG ◽  
JING HUANG ◽  
JIANLIANG CAO ◽  
GAOJIE LI ◽  
ZHANYING ZHANG
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Hydrothermal Method ◽  
Cobalt Oxide ◽  
Reaction Temperature ◽  
High Catalytic Activity ◽  
Total Conversion ◽  
Ft Ir ◽  
Excellent Stability

Co3O4 decorated flower-like g-C3N4 hybrid nanocatalysts were successfully synthesized and prepared via a facial hydrothermal method. The composition and morphology of the as-synthesized Co3O4/g-C3N4 nanocatalysts were characterized by the techniques of XRD, FT-IR, SEM, TEM, XPS and N2-sorption. The analysis results indicated that the as-synthesized samples possess the flower-like structure, which consisted of g-C3N4 nanosheets and Co3O4 nanoparticles with the size about 25[Formula: see text]nm. The as-prepared Co3O4/g-C3N4 catalysts possess high catalytic activity and excellent stability for carbon monoxide (CO) oxidation. The total conversion of Co can be kept for more than 48[Formula: see text]h under the reaction temperature of 120[Formula: see text]C.

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