scholarly journals n-Heptane isomerization activities of Pt catalyst supported on micro/mesoporous composites

BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Z. Ghaderi ◽  
M. H. Peyrovi ◽  
N. Parsafard
Keyword(s):  
Nitrogen Adsorption ◽  
Pt Catalyst ◽  
Isomerization Reaction ◽  
X Ray Diffraction ◽  
Hy Zeolite ◽  
Composite Catalysts ◽  
Isomerization Selectivity ◽  
Catalytic Stability ◽  
Adsorption Desorption ◽  
Heptane Conversion

AbstractPt loaded on a series of MCM-48 silica and composites with HZSM-5 zeolite, HY zeolite, or TiO2 has been prepared and studied for n-heptane isomerization reaction at 200–350 °C. The structural characterization, acid distribution, and morphology of these catalysts were characterized by X-ray diffraction, Fourier transform infrared, UV–Vis diffuse reflectance, scanning electron microscope, temperature-programmed desorption of NH3, and nitrogen adsorption–desorption methods. The results show that these catalysts have a good selectivity to multi branched isomers, while producing low aromatic compounds. Also, these new composite catalysts prove the catalytic stability during the time of reaction. The most desirable results, and significantly higher n-heptane conversion and isomerization selectivity were achieved with Pt/MCM48-HZSM5 catalyst.

n-Heptane Isomerization Activities of Pt Catalyst Supported On Micro/Mesoporous Composites

2021 ◽  
Author(s):  
Z. Ghaderi ◽  
M. H. Peyrovi ◽  
n. Parsafard
Keyword(s):  
Structural Characterization ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Pt Catalyst ◽  
Isomerization Reaction ◽  
Good Ability ◽  
Ft Ir ◽  
Mesoporous Composites ◽  
Adsorption Desorption ◽  
The Ideal

Abstract Pt loaded on a series of MCM-48 and composites with HZSM-5, HY or TiO2 has been prepared and studied for n-heptane isomerization reaction at 200–350°C. The structural characterization, acid distribution and morphology of these catalysts were characterized by XRD, FT-IR, UV-Vis DRS, SEM, NH3-TPD, and nitrogen adsorption-desorption methods. These new catalysts have good ability for n-heptane isomerization. The ideal catalytic performance was observed on Pt/MCM48-HZSM5 catalyst.

Application of raw and modified Uruguayan clays to phosphate adsorption for water remediation

MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3543-3549
Author(s):  
Pablo González ◽  
Andrea C. De Los Santos ◽  
Jorge R. Castiglioni ◽  
María A. De León
Keyword(s):  
Nitrogen Adsorption ◽  
Pillared Clay ◽  
Water Remediation ◽  
Phosphate Adsorption ◽  
X Ray Diffraction ◽  
Order Model ◽  
Freundlich Model ◽  
X Ray ◽  
First Order ◽  
Adsorption Desorption

ABSTRACTA raw clay from Uruguay was modified with aluminium to obtain an aluminium pillared clay (Al-PILC). The solids were characterized by scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherms. The Al-PILC retained the typical laminar structure of montmorillonite. The specific surface area and the microporous volume of the Al-PILC, 235 m2 g-1 and 0.096 cm3 g-1, respectively, were much higher than those of the clay. The phosphate adsorption capacity of the Al-PILC was higher than those of the clay. The phosphate adsorption kinetic followed the pseudo-first-order model for both, the clay and the Al-PILC, and the phosphate adsorption isotherm for the Al-PILC fit the Freundlich model.

NANOSEEDING EFFECT IN ZSM-5 CRYSTALLIZATION PROCESS

NANO ◽  
2013 ◽  
Vol 08 (03) ◽  
pp. 1350027
Author(s):  
YI LU ◽  
NAI-QIAN ZHANG ◽  
QIN TONG ◽  
JIN-KU LIU ◽  
DAN-JING HONG
Keyword(s):  
Crystallization Process ◽  
Nitrogen Adsorption ◽  
Particle Size Effect ◽  
Isomerization Reaction ◽  
Transmission Electron Micrograph ◽  
Electron Micrograph ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Induction System ◽  
Temperature Programmed

ZSM-5 zeolites were hydrothermally synthesized in three different seeding pathways under the direction of tetrapropylammonium bromide (TPABr) template. In order to investigate the seeding effect in ZSM-5 crystallization process, ZSM-5 crystals and pre-fabricated MFI-type nanoseeds were added into the original self-induction system, respectively. The final ZSM-5 zeolites were systematically investigated based on XRD (X-ray diffraction), SEM (scanning electron micrograph), TEM (transmission electron micrograph), nitrogen adsorption characterizations and NH3 -TPD (ammonia-temperature programmed desorption). The self-induction system produced ca. 20 μm ZSM-5 zeolite displaying hexagonally uniform prisms. After the addition of ZSM-5 crystal seeds, the crystal sizes were decreased greatly to ca. 5 μm. When MFI-type nanoseeds were adopted, irregular aggregate particles consisting of 20–50 nm primary particles were rapidly synthesized. The varied hydrothermal crystallization kinetics of the three synthesis system was also explored. Adjusting the seed agents alone, ZSM-5 crystals with diverse structural, morphological, textural and hydrothermal behaviors could be fabricated conveniently. The three ZSM-5 zeolites loaded by 0.05 wt.% Pt were assessed for the xylene isomerization reaction to investigate the particle size effect on the catalytic properties.

scholarly journals Highly Porous Carbon Materials Filled with Nickel Hydroxide Nanoparticles; Synthesis, Study, Application in Electrochemistry

2015 ◽  
Vol 17 (3) ◽  
pp. 187 ◽  
Author(s):  
Yu.A. Zakharov ◽  
A.N. Voropay ◽  
N.M. Fedorova ◽  
V.M. Pugachev ◽  
A.V. Puzynin ◽  
...  
Keyword(s):  
Porous Carbon ◽  
Nickel Hydroxide ◽  
Nitrogen Adsorption ◽  
Porous Carbon Material ◽  
X Ray Diffraction ◽  
Scanning Rate ◽  
Electrode Cell ◽  
Adsorption Desorption ◽  
Electrode Characteristics ◽  
Study Application

<p>Nickel hydroxide was deposited on the surface of the porous carbon to obtain a cathode material for supercapacitors. This work is the first part of the study of Ni(OH)<sub>2</sub>/С composite, which considers the conditions of its synthesis using two types of porous carbon matrices with a highly developed specific surface area (1000–3000 m<sup>2</sup>/g) and two types of precursors (NiCl<sub>2</sub>*6H<sub>2</sub>O and Ni(N<sub>3</sub>)<sub>2</sub>). The morphology of the systems, in particular the shape and size characteristics of the hydroxide filler particles, was examined using the scanning electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption at 77 K. The measurements of capacity of the Ni(OH)<sub>2</sub>/С-electrodes were made in 6 M KOH using an asymmetric two-electrode cell (a porous carbon material with known electrode characteristics was employed as the counter electrode). The capacity was shown to decrease by 22–56% with increasing the scanning rate from 10 to 80 mV/s. A maximum capacity of the composite was obtained at a scanning rate of 10 mV/s was 346 F/g.</p>

Structural and surface aspects of thermally treated copper aluminium mixed hydroxides

1991 ◽  
Vol 69 (10) ◽  
pp. 1511-1515 ◽  
Author(s):  
Awad I. Ahmed ◽  
S. E. Samra ◽  
S. A. El-Hakam
Keyword(s):  
Pore Structure ◽  
Copper Content ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Structure Surface ◽  
Adsorption Desorption

CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

scholarly journals Porosity Design of Shaped Zeolites for Improved Catalyst Lifetime in the Methanol-to-Hydrocarbons Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 545 ◽  
Author(s):  
Rogéria Bingre ◽  
Renna Li ◽  
Qiang Wang ◽  
Patrick Nguyen ◽  
Thomas Onfroy ◽  
...  
Keyword(s):  
Pore Volume ◽  
Active Sites ◽  
Coke Formation ◽  
Effective Diffusivity ◽  
Nitrogen Adsorption ◽  
Breakthrough Time ◽  
Methanol To Hydrocarbons ◽  
Catalytic Stability ◽  
Temperature Programmed ◽  
Adsorption Desorption

Additional porosity, such as meso- and macropores, was introduced in zeolite extrudates with the intention intuit of improving the effective diffusivity of the catalysts. The samples were characterized in depth by nitrogen adsorption-desorption, mercury intrusion porosimetry, ammonia temperature programmed desorption and adsorption of pyridine followed by infrared spectroscopy. The results revealed no significant change in the acidity but an increase of the pore volume. According to significant improvement in the effective diffusivity, the samples were tested in the methanol-to-hydrocarbons reaction. The catalytic stability was greatly enhanced with an increase in the pore volume, demonstrating a relation between effective diffusivity and resistance to deactivation by coke formation. Further experiments also revealed a higher toluene adsorption capacity and a raise in the breakthrough time over the most porous samples due to better accessibility of toluene molecules into the active sites of the zeolite.

scholarly journals Bulk Versus Surface Modification of Alumina with Mn and Ce Based Oxides for CH4 Catalytic Combustion

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1771 ◽  
Author(s):  
Stefan Neatu ◽  
Mihaela M. Trandafir ◽  
Adelina Stănoiu ◽  
Ovidiu G. Florea ◽  
Cristian E. Simion ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mixed Oxides ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Catalytic Combustion Of Methane ◽  
Adsorption Desorption

This study presents the synthesis and characterization of lanthanum-modified alumina supported cerium–manganese mixed oxides, which were prepared by three different methods (coprecipitation, impregnation and citrate-based sol-gel method) followed by calcination at 500 °C. The physicochemical properties of the synthesized materials were investigated by various characterization techniques, namely: nitrogen adsorption-desorption isotherms, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and H2–temperature programmed reduction (TPR). This experimental study demonstrated that the role of the catalytic surface is much more important than the bulk one. Indeed, the incipient impregnation of CeO2–MnOx catalyst, supported on an optimized amount of 4 wt.% La2O3–Al2O3, provided the best results of the catalytic combustion of methane on our catalytic micro-convertors. This is mainly due to: (i) the highest pore size dimensions according to the Brunauer-Emmett-Teller (BET) investigations, (ii) the highest amount of Mn4+ or/and Ce4+ on the surface as revealed by XPS, (iii) the presence of a mixed phase (Ce2MnO6) as shown by X-ray diffraction; and (iv) a higher reducibility of Mn4+ or/and Ce4+ species as displayed by H2–TPR and therefore more reactive oxygen species.

Preparation of Porous Carbon and its Composite Materials via the Reaction under Autogenic Pressure at Elevated Temperature (RAPET)

2018 ◽  
Vol 921 ◽  
pp. 60-64
Author(s):  
Ke Xun Li ◽  
Jiang Jiang Ma ◽  
Jie Zhang ◽  
Kun Jia ◽  
Bi Cheng Zhou ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Composite Materials ◽  
Porous Carbon ◽  
Nitrogen Adsorption ◽  
Inorganic Materials ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
X Ray Diffraction ◽  
Discharge Performance ◽  
Adsorption Desorption

In this paper, we reported on the preparation of porous materials via a reaction under Autogenic Pressure at Elevated Temperature (RAPET) at 700°Cusing natural product and alkoxides as precursors. The RAPET is a new simple efficient method to prepare inorganic materials. The porous carbon and its composite materials were prepared via the method of RAPET using natural products such as sweet potato, coriander, the absorbent cotton and viscose fiber doped by tetrabutyl titanate (TBOT) and tetraethoxysilane (TEOS). The reaction temperature of RAPET was 700°C. The carbon and its composites were studied with scanning electron microscopy (SEM), X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. The BET surface area of the materials are different from 4m2/g to 405m2/g. The XRD investigation indicates that the phases of the TiO2 in the carbon/TiO2 composites are anatase. The materials show a certain charge-discharge performance.

scholarly journals Effect of the Organobentonite Filler on Structure and Properties of Composites Based on Hydroxyethyl Cellulose

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Olga V. Alekseeva ◽  
Anna N. Rodionova ◽  
Nadezhda A. Bagrovskaya ◽  
Alexander V. Agafonov ◽  
Andrew V. Noskov
Keyword(s):  
Tensile Properties ◽  
Composite Films ◽  
Nitrogen Adsorption ◽  
Hydroxyethyl Cellulose ◽  
X Ray Diffraction ◽  
Ir Spectrometry ◽  
X Ray ◽  
Mechanical Dispersion ◽  
Filling Agent ◽  
Adsorption Desorption

Organobentonite powder was synthesized and characterized using laser diffraction, X-ray diffraction, low-temperature nitrogen adsorption-desorption technique, and dynamic light scattering. Obtained powder was found as material with mesopores. The organobentonite particles were larger than pure bentonite one. Hydroxyethyl cellulose (HEC) was filled with organobentonite particles by mechanical dispersion, and produced composite films were researched by the number of methods. New data relating to structure, tensile properties, and antimicrobial activity of HEC/organobentonite composites were obtained. Using results of X-ray diffraction, the reflections assigned to crystal filler in polymer material were proved. Concentration effect of the filling agent on tensile properties of composite film was revealed. Data of infrared (IR) spectrometry indicated a decrease in the density of hydrogen-bond net in HEC/organobentonite composite as compared with pristine HEC. Using microbiological tests, it was found that the HEC/organobentonite films exhibited bacteriostatic action against S. aureus and fungistatic action against molds.

Synthesis of SBA-15 under Normal Pressure by Microwave Irradiation Method for Adsorption of Pb(II) in Environment

2010 ◽  
Vol 113-116 ◽  
pp. 775-779 ◽  
Author(s):  
Yan Liu ◽  
Yun Wang ◽  
Xiao Jie Zhang ◽  
Ji Min Xie ◽  
Yong Sheng Yan
Keyword(s):  
Microwave Irradiation ◽  
River Sediments ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Normal Pressure ◽  
X Ray Diffraction ◽  
Microwave Irradiation Method ◽  
Equilibrium Data ◽  
Pseudo Second Order ◽  
Adsorption Desorption

Mesoporous silica SBA-15 has been prepared rapidly under normal pressure by microwave irradiation method. The textural properties were studied by low-angle X-ray diffraction (XRD) and nitrogen adsorption-desorption. The optimum adsorption conditions of Pb(Ⅱ) on SBA-15 was investigated. The results show that the adsorption kinetics follows a pseudo-second-order rate model and the experimental equilibrium data is fitted well by Langmuir adsorption isotherm. The adsorption capacity reaches 50.10 mg•g-1 which is much higher than that of hydrothermal synthesized samples. This adsorbent has been applied in the determination of Pb(Ⅱ) in river sediments samples.

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