scholarly journals Calcium Hydroxyapatite: A Highly Stable and Selective Solid Catalyst for Glycerol Polymerization

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1247
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Catalytic Activity ◽  
Calcium Hydroxyapatite ◽  
Polymerization Reaction ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Reaction Products ◽  
Icp Oes ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
The Stability

Calcium-based catalysts are of high interest for glycerol polymerization due to their high catalytic activity and large availability. However, their poor stability under reaction conditions is an issue. In the present study, we investigated the stability and catalytic activity of Ca-hydroxyapatites (HAps) as one of the most abundant Ca-source in nature. A stochiometric, Ca-deficient and Ca-rich HAps were synthesized and tested as catalysts in the glycerol polymerization reaction. Deficient and stochiometric HAps exhibited a remarkable 100% selectivity to triglycerol at 15% of glycerol conversion at 245 °C after 8 h of reaction in the presence of 0.5 mol.% of catalyst. Moreover, under the same reaction conditions, Ca-rich HAp showed a high selectivity (88%) to di- and triglycerol at a glycerol conversion of 27%. Most importantly, these catalysts were unexpectedly stable towards leaching under the reaction conditions based on the ICP-OES results. However, based on the catalytic tests and characterization analysis performed by XRD, XPS, IR, TGA-DSC and ICP-OES, we found that HAps can be deactivated by the presence of the reaction products themselves, i.e., water and polymers.

scholarly journals Calcium Hydroxyapatite: A Highly Stable and Selective Solid Catalyst for Glycerol Polymerization

2021 ◽  
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Catalytic Activity ◽  
Calcium Hydroxyapatite ◽  
Polymerization Reaction ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Reaction Products ◽  
Icp Oes ◽  
Reaction Conditions ◽  
Glycerol Conversion ◽  
The Stability

Abstract: Calcium-based catalysts are of a high interest for glycerol polymerization due to their high catalytic activity and large availability. However, their poor stability under reaction conditions is an issue. In the present study, we investigated the stability and catalytic activity of Ca-hydroxyapatites (HAps) as one of the most abundant Ca-source in nature. A stochiometric, a Ca-deficient and a Ca-rich HAps have been synthetized and tested as catalysts in the glycerol polymerization reaction. Deficient and stochiometric HAps exhibited a remarkable 100% selectivity to triglycerol at 15 % of glycerol conversion at 245 °C after 8 h of reaction in the presence 0.5 mol.% of catalyst. Moreover, under the same reaction conditions, Ca-rich HAp showed a high selectivity (88 %) to di- and triglycerol at a glycerol conversion of 27 %. Most importantly, these catalysts were unexpectedly stable towards leaching under the reaction conditions based on the ICP-OES results. However, based on the catalytic tests and characterization analysis performed by XRD, XPS, IR, TGA-DSC and ICP-OES, we found that HAps can be deactivated by the presence of the reaction products themselves, i.e., water and polymers.

Catalytic Synthesis of Benzyl Acetate by Diatomite Supported Waugh-Type (NH4)6[MnMo9O32] •8H2O

2013 ◽  
Vol 483 ◽  
pp. 38-41
Author(s):  
Shu Heng Liu
Keyword(s):  
Acetic Acid ◽  
Catalytic Activity ◽  
Reaction Time ◽  
Catalytic Synthesis ◽  
Orthogonal Test ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Benzyl Acetate ◽  
Reaction Conditions ◽  
Catalyst Dosage

Take Waugh-Type (NH4)6[MnMo9O32] •8H2O absorbed on diatomite and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 1.6g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 87.4%. The catalyst are high catalytic activity and non- polluting, and could be reused.

scholarly journals Perovskite-structured Active Solid Catalyst for Biofuel Synthesis

2019 ◽  
Vol 6 (1) ◽  
pp. 1-5
Author(s):  
Ahmed Umar ◽  
Musthafa Ottakam Thotyl ◽  
Abdullahi Hadi
Keyword(s):  
Catalytic Activity ◽  
Perovskite Structure ◽  
Reaction Times ◽  
Active Phase ◽  
Catalyst System ◽  
Transesterification Reaction ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Reaction Conditions ◽  
Renewable Fuel

Abstract A solid catalyst tailored to perovskite structure was synthesized and investigated for catalytic activity in a transesterification reaction to form biodiesel. The catalyst has demonstrated high catalytic activity and selectivity for biodiesel under very mild reaction conditions and short reaction times. The catalyst system has shown robust resistance to leaching of the active phase when reused. The performance was attributable to the perovskite structure and the dopant metal used. Hence, this work has shown that the structure and dopant metal of the solid catalyst could be tailored to enhance catalytic activity and durability for renewable fuel synthesis.

scholarly journals Synergistic Effects of Co3O4-CeO2 Nanoparticles towards Catalytic Oxidation of Aromatic Hydrocarbons: A Study in Association with Carbon Monoxide and Humidity

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Trung Dang-Bao ◽  
Hong Phuong Phan ◽  
Phung Anh Nguyen ◽  
Pham Phuong Trang Vo ◽  
Van Tien Huynh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Synergistic Effects ◽  
Active Oxygen Species ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Temperature Programmed ◽  
The Stability

In this study, a series of Co3O4-CeO2 nanocomposites with various Co3O4 loading were fabricated by the impregnation method using cobalt(II) acetate as the cobalt precursor for the treatment of benzene, toluene, ethylbenzene, and xylene (BTEX). The as-prepared Co3O4-CeO2 nanocomposites were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (O2-TPD). The excellent reproduction of active oxygen species caused by the high dispersion of Co3O4 crystals on the CeO2 supports was established. In addition, the reduction peaks of Co3O4-CeO2 nanocomposites were found at much lower temperatures compared to pure CeO2, considering their unique redox property influencing on the high catalytic activity. Among the characterized materials, the 5.0 wt.% Co3O4 supported on CeO2 (5.0Co–Ce) was the best system for catalytic oxidation of xylene, along with excellent performances in the cases of benzene, ethylbenzene, and toluene. Its catalytic activity increased in the order: benzene < xylene < ethylbenzene < toluene . Furthermore, the addition of carbon monoxide (CO) as a coreactant permitted to improve the catalytic performances in such oxidations as well as the stability of as-prepared catalysts, even under humid conditions.

scholarly journals Alkaline-Based Catalysts for Glycerol Polymerization Reaction: A Review

2020 ◽  
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Heterogeneous Catalysts ◽  
Antimicrobial Agents ◽  
Reaction Medium ◽  
Operating Conditions ◽  
Polymerization Reaction ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Glycerol Conversion ◽  
Advantages And Disadvantages ◽  
Wide Range

Polyglycerols (PGs) are biocompatible and highly functional polyols with a wide range of applications, such as emulsifiers, stabilizers, antimicrobial agents, in many industries including cosmetics, food, plastic and biomedical. The demand increase for biobased PGs encourages researchers to develop new catalytic systems for glycerol polymerization. This review focuses on alkaline homogeneous and heterogeneous catalysts. The performances of the alkaline catalysts are compared in terms of conversion and selectivity, and their respective advantages and disadvantages are commented. While homogeneous catalysts exhibit a high catalytic activity, they cannot be recycled and reused, whereas solid catalysts can be partially recycled. The key issue for heterogenous catalytic systems, which is unsolved so far, is linked to their instability due to partial dissolution in the reaction medium. Further, this paper also reviews the proposed mechanisms of glycerol polymerization over alkaline-based catalysts and discuss the various operating conditions with an impact on the performances. More particularly, temperature and amount of catalyst proved to have a significant influence on glycerol conversion and on its polymerization extent.

scholarly journals Alkaline-Based Catalysts for Glycerol Polymerization Reaction: A Review

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1021
Author(s):  
Negisa Ebadipour ◽  
Sébastien Paul ◽  
Benjamin Katryniok ◽  
Franck Dumeignil
Keyword(s):  
Heterogeneous Catalysts ◽  
Antimicrobial Agents ◽  
Reaction Medium ◽  
Operating Conditions ◽  
Polymerization Reaction ◽  
High Catalytic Activity ◽  
Catalytic Systems ◽  
Glycerol Conversion ◽  
Advantages And Disadvantages ◽  
Wide Range

Polyglycerols (PGs) are biocompatible and highly functional polyols with a wide range of applications, such as emulsifiers, stabilizers and antimicrobial agents, in many industries including cosmetics, food, plastic and biomedical. The demand increase for biobased PGs encourages researchers to develop new catalytic systems for glycerol polymerization. This review focuses on alkaline homogeneous and heterogeneous catalysts. The performances of the alkaline catalysts are compared in terms of conversion and selectivity, and their respective advantages and disadvantages are commented. While homogeneous catalysts exhibit a high catalytic activity, they cannot be recycled and reused, whereas solid catalysts can be partially recycled. The key issue for heterogenous catalytic systems, which is unsolved thus far, is linked to their instability due to partial dissolution in the reaction medium. Further, this paper also reviews the proposed mechanisms of glycerol polymerization over alkaline-based catalysts and discusses the various operating conditions with an impact on performance. More particularly, temperature and amount of catalyst are proven to have a significant influence on glycerol conversion and on its polymerization extent.

Study on Bio-Fuels Drop Acid by [BSPy]HSO4 Catalytic Esterification

2013 ◽  
Vol 781-784 ◽  
pp. 2433-2437 ◽  
Author(s):  
Ai Hua Zhang ◽  
Zhi Hong Xiao ◽  
Liang Bo Zhang ◽  
Ru Kuan Liu ◽  
Wu Hong Zhong ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Acid Value ◽  
Esterification Reaction ◽  
Process Conditions ◽  
High Catalytic Activity ◽  
Brønsted Acidic Ionic Liquid ◽  
The Stability ◽  
Acid Esterification

Research on the synthesis of BrOnsted acidic ionic liquid by the method of solvent, the pyrolysis bio-fuel with cornus wisoniana oil drop acid esterification reaction, the catalyst dosage, reaction time and reaction temperature on the effects of the acid dropping and in the best optimization under the condition of the stability of the catalyst were investigated. The experimental results show that [BSPHSO4 with high catalytic activity, optimization of process conditions as follows: 1.2% of catalyst, reaction temperature 75 °C, reaction time of 70 min, acid value reduced to 2.0 mg KOH/g. By optimizing the cycle experiment, the stability of the catalyst performance is good, the catalytic activity is relatively stable.

New Modeling of AgFeNi2S4-Graphene-TiO2 Ternary Nanocomposite with Chelate Compounds and Its Photocatalytic Reduction of CO2

2021 ◽  
Author(s):  
Zambaga Otgonbayar ◽  
Chong Hun Jung ◽  
Oh Won-Chun
Keyword(s):  
Catalytic Activity ◽  
Citric Acid ◽  
Solvothermal Method ◽  
High Catalytic Activity ◽  
Photogenerated Electrons ◽  
Methanol Formation ◽  
Nano Material ◽  
Chelate Compounds ◽  
The Stability ◽  
Reduction Of Co2

Abstract Herein, we synthesized the chalcogenide-quaternary nanocomposite loaded Graphene-based ternary photocatalyst via a modified solvothermal method. The preparation of quaternary nanocomposite was based on metallic citrate polymerization which used ethylene glycol (C2H6O2) and citric acid (C6H8O7) as chelate cations. The morphology and electrochemical properties of the as-prepared nano-material investigated by using a physical characterization equipment. Each result showed that the ternary photocatalyst was successfully synthesized and showed the low recombination rate of photogenerated electrons and holes, which defined the catalytic activity of the photocatalyst for CO2 evolution into hydrocarbon fuels under light irradiation. In addition, the stability and reusability of the photocatalyst were analyzed by a 6-times cycling test without loss of methanol formation by CO2 evolution. The graphene-based ternary photocatalyst offers a new nanomaterial with a new-model that protects the environment by showing high catalytic activity in reducing CO2 to methanol.

scholarly journals Catalytic Oxidative/Extractive Desulfurization of Model Oil using Transition Metal Substituted Phosphomolybdates-Based Ionic Liquids

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 639 ◽  
Author(s):  
Yunlei Li ◽  
Yanjie Zhang ◽  
Panfeng Wu ◽  
Caiting Feng ◽  
Ganglin Xue
Keyword(s):  
Catalytic Activity ◽  
Ionic Liquids ◽  
Transition Metal ◽  
Sulfur Removal ◽  
Oxidative Desulfurization ◽  
High Catalytic Activity ◽  
Reaction Conditions ◽  
Extraction Solvent ◽  
Model Oil ◽  
Optimal Reaction

Polyoxometalates based ionic liquids (POM-ILs) exhibit a high catalytic activity in oxidative desulfurization. In this paper, four new POM-IL hybrids based on transition metal mono-substituted Keggin-type phosphomolybdates, [Bmim]5[PMo11M(H2O)O39] (Bmim = 1-butyl 3-methyl imidazolium; M = Co2+, Ni2+, Zn2+, and Mn2+), have been synthesized and used as catalysts for the oxidation/extractive desulfurization of model oil, in which ILs are used as the extraction solvent and H2O2 as an oxidant under very mild conditions. The factors that affected the desulfurization efficiency were studied and the optimal reaction conditions were obtained. The results showed that the [Bmim]5[PMo11Co(H2O)O39] catalyst demonstrated the best catalytic activity, with sulfur-removal of 99.8%, 85%, and 63% for dibenzothiophene (DBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), and benzothiophene (BT), respectively, in the case of extraction combining with a oxidative desulfurization system under optimal reaction conditions (5 mL model oil (S content 500 ppm), n(catalyst) = 4 μmol, n(H2O2)/n(Substrate) = 5, T = 50 °C for 60 min with [Omim]BF4 (1 mL) as the extractant). The catalyst can be recycled at least 8 times, and still has stability and high catalytic activity for consecutive desulfurization. Probable reaction mechanisms have been proposed for catalytic oxidative/extractive desulfurization.

Catalytic Synthesis of Benzyl Acetate by Anion Exchange Resin Supported Waugh-Type (NH4)6[MnMo9O32] • 8H2O

2013 ◽  
Vol 750-752 ◽  
pp. 1227-1230
Author(s):  
Shu Heng Liu ◽  
Li Xia Wang ◽  
Lin Lin Guo ◽  
Hua Yuan ◽  
Feng Zhen Yang
Keyword(s):  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Catalytic Synthesis ◽  
Orthogonal Test ◽  
Solid Catalyst ◽  
High Catalytic Activity ◽  
Benzyl Acetate ◽  
Reaction Conditions ◽  
Catalyst Dosage

Take Waugh-Type (NH4)6[MnMo9O32]8H2O absorbed on anion exchange resin and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 0.4g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 95.4%. The catalyst are high catalytic activity and non-polluting, and could be reused.

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