A nona-vacant Keggin-type tricarbonyl rhenium derivative {[PMo3O16][Re(CO)3]4}5− and its catalytic performance for CO2 cycloaddition reactions

RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 69006-69009 ◽  
Author(s):  
Zhiyuan Huo ◽  
Jipeng Guo ◽  
Jingkun Lu ◽  
Qiaofei Xu ◽  
Pengtao Ma ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cycloaddition Reaction ◽  
Catalytic Performance ◽  
Cycloaddition Reactions ◽  
Frontier Orbitals ◽  
Keggin Type ◽  
Good Catalytic Activity

A nona-vacant Keggin-type tricarbonyl rhenium derivative {[PMo3O16][Re(CO)3]4}5− was synthesized and its frontier orbitals were computed. Interestingly, it showed good catalytic activity for the CO2 cycloaddition reaction.

scholarly journals Synthesis of Graphene-Based Biopolymer TiO2 Electrodes Using Pyrolytic Direct Deposition Method and its Catalytic Performance

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1050
Author(s):  
Parminder Kaur ◽  
Sana Frindy ◽  
Yuri Park ◽  
Mika Sillanpää ◽  
Monzur A. Imteaz
Keyword(s):  
Catalytic Activity ◽  
Municipal Wastewater ◽  
Catalytic Performance ◽  
Optimum Process ◽  
Self Healing ◽  
Pharmaceutical Drugs ◽  
Operational Parameters ◽  
Graphene Layers ◽  
Good Catalytic Activity ◽  
Chitosan Biopolymer

The traditional methods used to synthesize graphene layers over semiconductors are chemical-based methods. In the present investigation, a novel photoelectroactive electrode was synthesized using a chitosan biopolymer without the usage of chemicals. A chitosan-biopolymer layer over the surface of TiO2 was generated by electrodeposition. Furthermore, the pyrolysis method was used for the conversion of a biopolymer into graphene layers. The catalytic activity of the fabricated electrodes was investigated by the photo-electro-Fenton (PEF) process to oxidize chloramphenicol and nadolol pharmaceutical drugs in wastewater, remove metals (scandium, neodymium, and arsenic) and degrade real municipal wastewater. The PEF operational parameters (pH, voltage, reaction time, and Fenton catalytic dose) were optimized for the overall degradation of chloramphenicol and nadolol pharmaceutical drugs in wastewater. It was observed that at the optimum process operational parameters it took 40 min to degrade chloramphenicol and nadolol pharmaceutical drugs in wastewater. It was proved that biopolymer-based photoelectroactive novel electrodes render good catalytic activity. Furthermore, the reusability study of fabricated electrodes showed excellent storage and self-healing properties.

Inverse relationship of dimensionality and catalytic activity in CO2transformation: a systematic investigation by comparing multidimensional metal–organic frameworks

2017 ◽  
Vol 5 (30) ◽  
pp. 15961-15969 ◽  
Author(s):  
Robin Babu ◽  
Roshith Roshan ◽  
Yeongrok Gim ◽  
Yun Hee Jang ◽  
Jintu Francis Kurisingal ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Inverse Relationship ◽  
Metal Organic Frameworks ◽  
Catalytic Performance ◽  
Systematic Investigation ◽  
Cycloaddition Reactions ◽  
Metal Organic ◽  
Relationship Of

The correlation between dimensionality and active sites on deciding the catalytic performance of an MOF catalyst in CO2–epoxide cycloaddition reactions has been studied.

scholarly journals Comparison of Catalytic Activity of ZIF-8 and Zr/ZIF-8 for Greener Synthesis of Chloromethyl Ethylene Carbonate by CO2 Utilization

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 521 ◽  
Author(s):  
Bisi Olaniyan ◽  
Basudeb Saha
Keyword(s):  
Catalytic Activity ◽  
Large Scale ◽  
Mechanical Stability ◽  
Ethylene Carbonate ◽  
Direct Synthesis ◽  
Cycloaddition Reaction ◽  
Catalytic Performance ◽  
Industrial Applications ◽  
Catalyst Loading ◽  
Solvent Free Conditions

The catalytic activity of both ZIF-8 and Zr/ZIF-8 has been investigated for the synthesis of chloromethyl ethylene carbonate (CMEC) using carbon dioxide (CO2) and epichlorohydrin (ECH) under solvent-free conditions. Published results from literature have highlighted the weak thermal, chemical, and mechanical stability of ZIF-8 catalyst, which has limited its large-scale industrial applications. The synthesis of novel Zr/ZIF-8 catalyst for cycloaddition reaction of ECH and CO2 to produce CMEC has provided a remarkable reinforcement to this weak functionality, which is a significant contribution to knowledge in the field of green and sustainable engineering. The enhancement in the catalytic activity of Zr in Zr/ZIF-8 can be attributed to the acidity/basicity characteristics of the catalyst. The comparison of the catalytic performance of the two catalysts has been drawn based on the effect of different reaction conditions such as temperature, CO2 pressure, catalyst loading, reaction time, stirring speed, and catalyst reusability studies. Zr/ZIF-8 has been assessed as a suitable heterogeneous catalyst outperforming the catalytic activities of ZIF-8 catalyst with respect to conversion of ECH, selectivity and yield of CMEC. At optimum conditions, the experimental results for direct synthesis of CMEC agree well with similar literature on Zr/MOF catalytic performance, where the conversion of ECH, selectivity and the yield of CMEC are 93%, 86%, and 76%, respectively.

Soluble imidazolium-functionalized coordination cages for efficient homogeneous catalysis of CO2 cycloaddition reactions

2021 ◽  
Author(s):  
Hui-Ying Tong ◽  
Jun Liang ◽  
Qiu-Jin Wu ◽  
Yu-Huang Zou ◽  
Yuan-Biao Huang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Homogeneous Catalysis ◽  
Cycloaddition Reaction ◽  
Homogeneous Catalyst ◽  
Cycloaddition Reactions ◽  
Coordination Cages ◽  
Metal Organic ◽  
Activity Loss ◽  
Recovery And Reuse

The soluble metal–organic cage ImBDC-Co can be employed as a homogeneous catalyst for the CO2 cycloaddition reaction, and shows higher catalytic activity than its heterogeneous counterparts. Moreover, the soluble cage can realize recovery and reuse without activity loss.

Efficient Catalysts of Acyclic Guanidinium Iodide for the Synthesis of Cyclic Carbonates from Carbon Dioxide and Epoxides under Mild Conditions

Synthesis ◽  
2019 ◽  
Vol 52 (01) ◽  
pp. 150-158 ◽  
Author(s):  
Naoto Aoyagi ◽  
Yoshio Furusho ◽  
Takeshi Endo
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Cycloaddition Reactions ◽  
Cyclic Carbonates ◽  
Polar Solvents ◽  
Mild Conditions ◽  
Iodide Ion ◽  
Good Catalytic Activity ◽  
High Yields ◽  
Guanidinium Salts

We have studied the synthesis of five-membered cyclic carbonates through the cycloaddition of CO2 to epoxides by using acyclic guanidinium salts. We have found that the cycloaddition reactions proceed smoothly at ordinary temperatures and pressures and result in good yields when acyclic guanidinium iodides are employed as catalysts. Both cation moiety and anion moiety of the guanidinium salts play important roles in their catalytic activity. It is essential to have active hydrogens on the cation moiety as well as an iodide ion as the anion moiety so as to achieve good catalytic activity. Guanidinium iodides with three or more active hydrogens give cyclic carbonates in high yields in polar solvents such as 1-methylpyrrolidin-2-one, whereas the guanidinium iodides with one or two active hydrogens show good catalytic activity in less polar solvents such as 2-methyltetrahydrofuran.

Catalytic Synthesis of Dioctyl Phthalate over Al-MCM-41 Molecular Sieves

2011 ◽  
Vol 306-307 ◽  
pp. 1741-1746
Author(s):  
Hua Feng Zhou ◽  
Yong Jin Yang ◽  
Jin Son Zhang
Keyword(s):  
Catalytic Activity ◽  
Molecular Sieves ◽  
Hydrothermal Process ◽  
Analytical Techniques ◽  
Catalytic Performance ◽  
Dioctyl Phthalate ◽  
Catalytic Synthesis ◽  
Al Content ◽  
Good Catalytic Activity ◽  
Mcm 41

In this paper, mesoporous MCM-41 and Al-MCM-41(Si/Al =100, 70, 40, 10, 5) molecular sieves were synthesized by direct hydrothermal process and characterized by various analytical techniques. Their catalytic performance in the synthesis of dioctyl phthalate (DOP) was also studied. The results show that while keeping the mesostructure of Al-MCM-41(Si/Al=100, 70, 40), increasing Al content can increase the acidity and so forth effectively improve the catalytic activity. But too much aluminum incorporation can destroy the structure of Al-MCM-41(Si/Al=10). The Al-MCM-41 molecular sieves with proper Si/Al ratios have good catalytic activity and stability in DOP synthesis. When Al-MCM-41(40) was used as the catalyst, A high PA conversion of 98.45% can be reached in 4 h. After being reused for five times, Al-MCM-41(40) still remains good catalytic activity.

scholarly journals Efficient Production of Methyl Oleate Using a Biomass-Based Solid Polymeric Catalyst with High Acid Density

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Anping Wang ◽  
Heng Zhang ◽  
Hu Li ◽  
Song Yang
Keyword(s):  
Catalytic Activity ◽  
Oleic Acid ◽  
Methyl Oleate ◽  
Low Cost ◽  
Catalytic Performance ◽  
Raw Material ◽  
Efficient Production ◽  
High Acid ◽  
High Efficient ◽  
Good Catalytic Activity

Biomass-based polymers are eco-friendly, nontoxic and biodegradable materials. In this work, in order to prepare green, low-cost and high-efficient catalysts under mild conditions, we chose biomass-based chitosan as raw material and prepared a new solid acidic catalyst by an acid functionalization method. FT-IR, XRD, SEM, TGA, BET, neutralization titration and other analytical methods were used to characterize the catalyst. The results showed that CS-SO3H morphology exhibited a sphere of about 10 μm diameter, and the acid density was as high as 3.81 mmol/g. The catalyst exhibits good catalytic activity in the esterification of oleic acid and methanol, which is a model reaction of the pre-esterification process in the preparation of biodiesel from feedstocks with high acid values. Under the optimum reaction conditions (15/1 methanol/oleic acid mole ratio and 3 wt% catalyst dosage at 75°C for 3 h), the yield of methyl oleate can reach 95.7%. Even if the mass of oleic acid in the reactant increased to 20 g, solid acid showed good catalytic performance, and the yield of methyl oleate was 94.4%. After four times of reuse, the yield of the catalyst can still reach 85.7%, which indicates that the catalyst has good catalytic activity and stability, and has potential application prospects.

High resolution electron microscopy of lanthanum phosphate crystals

1978 ◽  
Vol 36 (1) ◽  
pp. 274-275
Author(s):  
J. C. Wheatley ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
High Resolution ◽  
Petroleum Industry ◽  
High Resolution Electron Microscopy ◽  
Lanthanum Phosphate ◽  
Good Catalyst ◽  
Resolution Electron ◽  
Good Catalytic Activity ◽  
Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

2019 ◽  
Vol 9 (3) ◽  
pp. 811-821 ◽  
Author(s):  
Zhao-Meng Wang ◽  
Li-Juan Liu ◽  
Bo Xiang ◽  
Yue Wang ◽  
Ya-Jing Lyu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Active Sites ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

scholarly journals CO Oxidation Efficiency and Hysteresis Behavior over Mesoporous Pd/SiO2 Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 131 ◽  
Author(s):  
Rola Mohammad Al Soubaihi ◽  
Khaled Mohammad Saoud ◽  
Myo Tay Zar Myint ◽  
Mats A. Göthelid ◽  
Joydeep Dutta
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Active Sites ◽  
Bond Activation ◽  
Dissociative Adsorption ◽  
High Catalytic Activity ◽  
Good Catalytic Activity ◽  
Pretreatment Conditions ◽  
Oxidation Efficiency

Carbon monoxide (CO) oxidation is considered an important reaction in heterogeneous industrial catalysis and has been extensively studied. Pd supported on SiO2 aerogel catalysts exhibit good catalytic activity toward this reaction owing to their CO bond activation capability and thermal stability. Pd/SiO2 catalysts were investigated using carbon monoxide (CO) oxidation as a model reaction. The catalyst becomes active, and the conversion increases after the temperature reaches the ignition temperature (Tig). A normal hysteresis in carbon monoxide (CO) oxidation has been observed, where the catalysts continue to exhibit high catalytic activity (CO conversion remains at 100%) during the extinction even at temperatures lower than Tig. The catalyst was characterized using BET, TEM, XPS, TGA-DSC, and FTIR. In this work, the influence of pretreatment conditions and stability of the active sites on the catalytic activity and hysteresis is presented. The CO oxidation on the Pd/SiO2 catalyst has been attributed to the dissociative adsorption of molecular oxygen and the activation of the C-O bond, followed by diffusion of adsorbates at Tig to form CO2. Whereas, the hysteresis has been explained by the enhanced stability of the active site caused by thermal effects, pretreatment conditions, Pd-SiO2 support interaction, and PdO formation and decomposition.

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