Oxidative Removal of Dibenzothiophene by H2O2 over Activated Carbon-Supported Phosphotungstic Acid Catalysts

2010 ◽  
Vol 132 ◽  
pp. 126-132 ◽  
Author(s):  
Guo Xian Yu ◽  
Rui Xue Zhou ◽  
Ji Bing Li ◽  
Xiao Long Zhou ◽  
Cheng Lie Li ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Phosphotungstic Acid ◽  
Carbon Support ◽  
Molar Ratio ◽  
N2 Adsorption ◽  
Oxidative Removal ◽  
Loading Amount ◽  
Model Oil ◽  
Adsorption Desorption ◽  
Sulfur Containing

Phosphotungstic acid (HPW) supported on activated carbon (AC) combined with hydrogen peroxide formed an oxidative desulfurizaiton (ODS) system to oxidize sulfur-containing compounds in diesel fuel. Dibenzothiophene (DBT) dissolved in n-octane was selected as a model feedstock for studying this new ODS system. The HPW/AC catalysts were characterized with XRD, FTIR and N2 adsorption-desorption measurements. HPW was highly dispersed on the surface of carbon support. It was found that the DBT adsorption capacity decreased from 42 mg S/g to 33.13 mg S/g as HPW loading amount increased from 0 to 15 wt.%. Oxidative removal of DBT in the model oil significantly increased with increasing HPW loadings on the support from 0 to 10 wt.%. 100 % DBT was removed by using the catalysts with HPW content higher than 10 wt. %. At 80 °C, oxidative removal of DBT reached 100 % after 40 min of reaction when O/S molar ratio ranged from 4 to 10.

scholarly journals Catalytic Performance of Phosphorus Incorporated HZSM-5 in Coupling Transformation of Methanol with 1-butene to Propylene

2021 ◽  
Vol 72 (3) ◽  
pp. 33-44
Author(s):  
Haifeng Tian ◽  
Yongyong Nan ◽  
Jinlong Lv ◽  
Fei Zha ◽  
Xiaohua Tang ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
N2 Adsorption ◽  
Facile Hydrothermal Method ◽  
Phosphorus Species ◽  
Coupling Transformation ◽  
Ft Ir ◽  
Adsorption Desorption

Directly incorporated phosphorus species into the framework of HZSM-5 zeolite (H[P, Al]-ZSM-5) was successfully synthesized by the facile hydrothermal method. It was characterized by employing XRD, ICP-OES, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD, XPS and TG-DTA, respectively. The effects of the phosphorus species content, temperature, WHSV, and the molar ratio of methanol/1-butene in coupling transformation of methanol with 1-butene to propylene catalyzed by H[P, Al]-ZSM-5 in a fixed bed reactor were studied systematically. Tests have suggested the acid content and specific surface area of H[P, Al]-ZSM-5 are reduced. Under the condition of reaction temperature at 550�Z, molar ratio of methanol/1-butene to 1.0, reaction pressure at 0.1 MPa and WHSV= 3.53 h-1, the P-modified HZSM-5 zeolite (with the P2O5 molar composition of 0.4 )the selectivity and yield of propylene are 35.6% and 32.5%, respectively.

scholarly journals Swift Reduction of Nitroaromatics By Gold Nanoparticles Anchored On Steam-Activated Carbon Black Via Simple Preparation

2021 ◽  
Author(s):  
Yukui Fu ◽  
Cui Lai ◽  
Wenjing Chen ◽  
Huan Yi ◽  
Xigui Liu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Carbon Black ◽  
Catalytic Performance ◽  
Metal Nanoparticle ◽  
Simple Method ◽  
Au Nps ◽  
Nanoparticle Catalysts ◽  
Loading Amount ◽  
Adsorption Desorption ◽  
Desorption Method

Abstract Gold (Au) nanoparticles supported on certain platforms display highly efficient activity on nitroaromatics reduction. In this study, steam-activated carbon black (SCB) was used as a platform to fabricate Au/SCB catalysts via a green and simple method for 4-nitrophenol (4-NP) reduction. The obtained Au/SCB catalysts exhibit efficient catalytic performance in reduction of 4-NP (rate constant kapp = 2.1925 min-1). The effects of SCB activated under different steam temperature, Au loading amount, pH and reaction temperature were studied. The structural advantages of SCB as a platform were analyzed by various characterizations. Especially, the result of N2 adsorption-desorption method showed that steam activating process could bring higher surface area (from 185.9689 m²/g to 249.0053 m²/g), larger pore volume (from 0.073268 cm³/g to 0.165246 cm³/g) and more micropore for SCB when compared with initial CB, demonstrating the suitable of SCB for Au NPs anchoring, thus promoting the catalytic activity. This work contributes to the fabrication of other supported metal nanoparticle catalysts for preparing different functional nanocomposites for different applications.

scholarly journals Enhancement of Light Olefins Selectivity Over N-Doped Fischer-Tropsch Synthesis Catalyst Supported on Activated Carbon Pretreated with KMnO4

Catalysts ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 505
Author(s):  
Zhipeng Tian ◽  
Chenguang Wang ◽  
Zhan Si ◽  
Chengyan Wen ◽  
Ying Xu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Carbon Support ◽  
Tropsch Synthesis ◽  
Light Olefins ◽  
Molar Ratio ◽  
Iron Nitride ◽  
Fischer Tropsch ◽  
Fischer Tropsch Synthesis ◽  
Suppression Effect ◽  
Light Olefins Selectivity

Ammonium iron citrate was used as an iron precursor in order to prepare N-doped catalysts supported on KMnO4 pretreated activated carbon (10MnK-AC). Iron nitride was synthesized in company with the formation of α-Fe2O3 on 10MnK-AC. The characterizations of the catalysts show that nitrogen atoms were doped into iron lattice rather than the networks of the carbon support. The performance of Fischer-Tropsch synthesis to light olefins (FTO) suggest an improvement in O/P ratio (olefins to paraffins molar ratio of C2–C4) over the iron catalysts supported on 10MnK-AC. The further promotion of light olefins selectivity (up to 44.7%) was obtained over FeN-10MnK-AC catalyst owing to the collaborative contribution of the electron donor effect of nitrogen and the suppression effect on the second hydrogenation over 10MnK-AC support.

scholarly journals Effect of the simultaneous presence of sodium and potassium cations on the hydrothermal synthesis of MCM-22 zeolite

2021 ◽  
Vol 10 (14) ◽  
pp. e192101421744
Author(s):  
Paulo Henrique Leite Quintela ◽  
Wellington Siqueira Lima ◽  
Bruno José Barros da Silva ◽  
Antonio Osimar Sousa da Silva ◽  
Meiry Gláucia Freire Rodrigues
Keyword(s):  
Hydrothermal Synthesis ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
Reaction Systems ◽  
X Ray ◽  
Time Required ◽  
The Cost ◽  
Adsorption Desorption ◽  
Sodium And Potassium

The hydrothermal synthesis of MCM-22 zeolite was investigated in reaction systems with different proportions of sodium and potassium cations. The potassium content R, defined as the molar ratio between potassium and the total inorganic cations amounts in the synthesis mixture, varied from 0 to 0.9, keeping constant the cationic concentration and the alkalinity of the system. The materials were characterized by X-ray diffraction (XRD), N2 adsorption/desorption and scanning electron microscopy (SEM). The K+ ions favored the formation of MCM-22 when 45% of sodium was replaced by potassium, reducing the time required to synthesize the MCM-22(P) precursor and producing more crystalline samples. Furthermore, the relative amounts of Na+ and K+ ions remarkably affected the morphology and particle size of the samples. The use of higher potassium contents (R = 0.68 – 0.9) hindered the crystallization of MCM-22 zeolite. Thus, the use of reaction mixtures with adequate proportions of Na+ and K+ can be an effective strategy to produce highly crystalline samples in shorter times, reducing the cost of synthesis of such zeolite

MgAl2O4 spinel-type as highly efficient catalyst for one-pot synthesis of 4H-pyrans

2022 ◽  
Vol 16 ◽  
Author(s):  
Mustapha Dib ◽  
Marieme Kacem ◽  
Soumaya Talbi ◽  
Hajiba Ouchetto ◽  
Khadija Ouchetto ◽  
...  
Keyword(s):  
Ethyl Acetoacetate ◽  
Room Temperature ◽  
Aromatic Aldehydes ◽  
Molar Ratio ◽  
Green Solvents ◽  
N2 Adsorption ◽  
One Pot ◽  
Ft Ir ◽  
The One ◽  
Adsorption Desorption

Background: Pyran is an heterocyclic oxygen-containing compound that displays a wide range of therapeutic activities. Additionally, pyran is also one of the important structural subunits widely found in pharmaceuticals products. This makes it a recent focus for researchers from the industry and academic institutions. Herein, we reported an efficient and environmentally friendly one-pot strategy for the synthesis of bioactive 4H-pyran compounds via a multicomponent reaction of ethyl acetoacetate, malononitrile and substituted aromatic aldehydes in the presence of the heterogeneous spinel catalyst ( MgAl2O4 ) under mild conditions (room temperature and green solvents). The MgAl2O4 nanocatalyst was prepared from Mg/Al-LDH with a molar ratio 3 of Mg2+/Al3+ by heat treatment at 800°C. The samples were studied by a various characterization techniques such as XRD, TG-dTG, FT-IR and N2 adsorption-desorption. Good to excellent yields and facile separation of the catalyst from the reaction mixture are two of the most appealing features of this approach. Thus, bioactive molecules with pyran units may have fascinating biological properties. An efficient and green strategy for the one-pot synthesis of bioactive 4H-pyran compounds has been described. The pyrans heterocycles were produced by multicomponent reaction of ethyl acetoacetate, malononirile and substituted aromatic aldehydes in the presence of MgAl2O4 spinel nanocatalyst under mild conditions (room temperature and green solvents). MgAl2O4 nanocatalytst was prepared from Mg/Al-LDH with a molar ratio 3 of Mg2+/Al3+ by thermal treatment at 800°C. The samples were investigated by various characterization techniques such as XRD, TG-dTG, FT-IR and N2 adsorption-desorption. The following are the appealing qualities of this unique strategy including good to exceptional yields, and ease of separation of catalyst from the reaction mixture. Thus, the obtained bioactive compounds containing pyrans motif can be exhibiting interested biological activities. Methods: The substituted 4H-pyran compounds were carried out by condensation reaction of substituted aromatic aldehydes, ethyl ethyl acetoacetate and malononirile by using MgAl2O4 nanocatalyst under sustainable conditions. Objective: To develop an efficient methodology for synthesis of 4H-pyran heterocyclic molecules may have interesting applications in biology using a heterogeneous and easily synthesized catalyst. Results: This procedure outlines the synthesis of bioactive compounds in good yields and with ease of catalyst extraction from the reaction mixture under sustainable reaction conditions. Conclusion: In conclusion, it is important to reiterate that a spinel nanostucture has been successfully prepared and fully characterized using different physicochemical analysis methods. The catalytic activity of this heterogeneous catalyst was examined through the one-pot condensation of aryl benzaldehyde, malononitrile and ethyl acetoacetate. Therefore, we have developed a green method for the preparation of 4H-pyrans derivatives using MgAl2O4 as an efficient heterogeneous catalyst. The reactions were performed under green conditions, which have many benefits such as undergoing a simple procedure, good to excellent yields and easy to separate the catalyst.

scholarly journals Bimetallic MOF-Derived Synthesis of Cobalt-Cerium Oxide Supported Phosphotungstic Acid Composites for the Oleic Acid Esterification

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qiuyun Zhang ◽  
Xianju Yang ◽  
Jiali Yao ◽  
Jingsong Cheng
Keyword(s):  
Oleic Acid ◽  
Cerium Oxide ◽  
Energy Production ◽  
Phosphotungstic Acid ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Significant Activity ◽  
Activity Loss ◽  
Adsorption Desorption ◽  
Acid Esterification

The impregnation of phosphotungstic acid (HPW) with porous cobalt-cerium oxide (HPW@CoCeO) has been prepared by pyrolysis of CoCe-MOF and used for the production of methyl oleate from oleic acid and methanol. FTIR, XRD, SEM, TEM, N2 adsorption/desorption, and NH3-TPD were characterized for the prepared composites. Simultaneously, the effects of reaction time, substrate molar ratio, temperature, and catalyst loading on catalytic activity were highlighted, and the conversion of 67.2% was reached after 4 h at 60°C. Importantly, HPW@CoCeO was reusabe and reused more than eight times, and the oleic acid conversion could be maintained at 61.8% without significant activity loss. Thus, the HPW@CoCeO composite could be used as acid catalysts for sustainable energy production.

Adsorption/desorption properties of activated carbon on toluene with operation condition and characteristics

2015 ◽  
Vol 14 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Seo-Hyun Pak ◽  
◽  
Myung-Seop Shin ◽  
Hyun-Jung Kim ◽  
Yong-Woo Jeon
Keyword(s):  
Activated Carbon ◽  
Operation Condition ◽  
Adsorption Desorption

scholarly journals Nanosheet-Like Ho2O3 and Sr-Ho2O3 Catalysts for Oxidative Coupling of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 388
Author(s):  
Yuqiao Fan ◽  
Changxi Miao ◽  
Yinghong Yue ◽  
Weiming Hua ◽  
Zi Gao
Keyword(s):  
Oxidative Coupling ◽  
Temperature Programmed Desorption ◽  
Oxidative Coupling Of Methane ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Oxygen Species ◽  
N2 Adsorption ◽  
Basic Sites ◽  
Chemisorbed Oxygen ◽  
Temperature Programmed

In this work, Ho2O3 nanosheets were synthesized by a hydrothermal method. A series of Sr-modified Ho2O3 nanosheets (Sr-Ho2O3-NS) with a Sr/Ho molar ratio between 0.02 and 0.06 were prepared via an impregnation method. These catalysts were characterized by several techniques such as XRD, N2 adsorption, SEM, TEM, XPS, O2-TPD (temperature-programmed desorption), and CO2-TPD, and they were studied with respect to their performances in the oxidative coupling of methane (OCM). In contrast to Ho2O3 nanoparticles, Ho2O3 nanosheets display greater CH4 conversion and C2-C3 selectivity, which could be related to the preferentially exposed (222) facet on the surface of the latter catalyst. The incorporation of small amounts of Sr into Ho2O3 nanosheets leads to a higher ratio of (O− + O2−)/O2− as well as an enhanced amount of chemisorbed oxygen species and moderate basic sites, which in turn improves the OCM performance. The optimal catalytic behavior is achievable on the 0.04Sr-Ho2O3-NS catalyst with a Sr/Ho molar ratio of 0.04, which gives a 24.0% conversion of CH4 with 56.7% selectivity to C2-C3 at 650 °C. The C2-C3 yield is well correlated with the amount of moderate basic sites present on the catalysts.

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