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Efficient catalytic system for carboxylation of alkynes employing carbon dioxide
( Mujmule Rajendra Basavant ),김헌 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
Carbon dioxide utilization has attracted great attention from researchers due to environmental problems and global warming. However, conversion of CO<sub>2</sub> is a great challenge due to the thermodynamic stability and kinetic inertness of CO<sub>2</sub>. With the increasing awareness of the ever-growing carbon dioxide levels in the atmosphere, great effort has been made to develop strategies and technologies towards the reduction of carbon emission. In this work, we have introduced efficient ionic liquid based catalytic system for the carboxylation of alkynes with CO<sub>2</sub> under mild reaction condition to produce the corresponding carboxylic esters. In addition, various parameters such as reaction temperature, pressure, reaction time, and reusability of catalyst are investigated.
( Mujmule Rajendra Basavant ),김헌 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
The heterogeneous catalyst was synthesized via immobilization of n-vinyl imidazolium-based ionic liquid on the carbonaceous material and used for chemical fixation of naturally abundant, non-toxic CO2 with an epoxide into cyclic carbonate without the aid of solvent and co-catalyst. The synthesized heterogeneous catalyst was characterized by spectroscopic methods. The catalytic properties were analysed by varying different reaction parameters, including the amount of catalyst, temperature, pressure, time and epoxide. The catalyst has exhibited excellent catalytic performance under the mild reaction condition. Moreover, results show that the catalyst has shown superior catalytic activity due to reactive acidic C(2) -H in imidazolium ring with hydroxyl (-OH) and carboxylic (-COOH) functional group-containing carbonaceous material which showed a synergistic effect.
Mujmule, Rajendra B.,Raghav Rao, M.P.,Rathod, Pramod V.,Deonikar, Virendrakumar G.,Chaugule, A.A.,Kim, Hern Elsevier 2019 Journal of CO<SUB>2</SUB> utilization Vol.33 No.-
<P><B>Abstract</B></P> <P>Carbon dioxide (CO<SUB>2</SUB>) mitigation via utilization can be a potential solution to global warming issues such as increasing CO<SUB>2</SUB> concentration. In this study, we present the synthesis and characterisation of 3-(2-hydroxyethyl)-1-vinyl-1H-imidazol-3-ium chloride [EvimOH][Cl] and 3-(2-hydroxyethyl)-1-vinyl-1H-imidazol-3-ium sulphate [EvimOH][HSO<SUB>4</SUB>] ionic liquids for cycloaddition reactions of CO<SUB>2</SUB> and epoxides into cyclic carbonates. The synthesized ionic liquids were characterized by FT-IR, <SUP>1</SUP>H- and <SUP>13</SUP>C-NMR spectroscopic methods. Also, we have analysed the physical properties of ionic liquids by using TGA and DTA. Further, the CO<SUB>2</SUB> consumption was done by developing a binary catalytic system with bases such as DBU, TEA, DIPEA, piperidine, pyrrolidine, aniline. The developed binary ([EvimOH][Cl]/base) catalytic system exhibited the excellent catalytic activity of 99.8% conversion and ≥99% selectivity under mild reaction conditions without the aid of solvent and metal co-catalysts. Furthermore, the results show that the improved activity from the binary system is due to synergistic effect among −OH functional group from the cation, reactive acidic C(2)-H in the imidazolium ring and amine containing bases which promote the CO<SUB>2</SUB> absorption. Also, a plausible mechanism of cyclic carbonate formation and kinetic study in the presence of binary catalytic system was demonstrated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of [EvimOH][Cl] and [EvimOH][HSO<SUB>4</SUB>] ionic liquids. </LI> <LI> The developed binary catalytic system of [EvimOH][Cl]/DBU and [EvimOH][HSO<SUB>4</SUB>]/DBU. </LI> <LI> Efficient Cycloaddition reaction of epoxides and CO<SUB>2</SUB>. </LI> <LI> Based on our results, a possible reaction mechanism has predicted, and also examined the reaction kinetics. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Benzimidazole-Based Ionic Porous Polymer for Effective CO₂ Enrichment and Utilization
Rajendra Mujmule,김헌 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2
Currently, it is essential to consider the rapidly increasing emission of carbon dioxide (CO₂) into the atmosphere. It is mostly produced from the combustion of fossil fuels and is considered a major greenhouse gas. Now, CO₂ capture and utilization from flue gases are being considered as the best option to mitigate the greenhouse effect for the industrial combustion process. The incorporation of numerous functional components into a composite material could lead to greater activity tailored to certain applications. Herein, multifunctional benzimidazole-based ionic porous polymer was constructed for efficient CO₂ absorption and utilization. The proposed polymer possess favourable structure features and good catalytic properties and displayed synergistic effect for both CO₂ absorption and utilization.
Deonikar, Virendrakumar G.,Mujmule, Rajendra B.,Patil, Deepak R.,Kim, Hern Elsevier 2019 The Science of the total environment Vol.675 No.-
<P><B>Abstract</B></P> <P>With the aim to develop an eco-friendly, efficient and stable photocatalyst, the present work reports the synthesis of Ag<SUB>3</SUB>PO<SUB>4</SUB>/LaCO<SUB>3</SUB>OH (AP/LC) heterojunction photocatalysts. Different weight ratios of AP/(x wt% LC) were tested to find the best composition for superior photocatalytic activity for dye pollutant degradation. AP/LC (20 wt%) revealed a superior photocatalytic activity. Hence it was selected for further analyses. Furthermore, we investigated the influence of distilled water: tetrahydrofuran (DW:TF) solvent system on the morphology as well as photocatalytic activities of AP/LC (20%) heterojunction. FESEM analysis shows that the morphology of AP/LC heterojunctions varied significantly with TF:DW ratio. Sphere-shaped like nanoparticles of LC transformed into nanowires to make intimate contact with AP polyhedras. The increase of TF with respect to DW results increase in the width of wire-like dimension of LC causes loose intimate contact within AP/LC heterojunction. The photocatalytic performance of AP/LC heterojunctions were tested against degradation of toxic phenol contaminant, and the outstanding photocatalytic activity was noticed for the AP/LC-2 photocatalyst (~99% degradation in 120 min) with a rate constant, <I>k</I> of 1.281 × 10<SUP>−2</SUP> min<SUP>−1</SUP>. The improved photocatalytic performance can be attributed to the uniform decoration of LC nanowires on the AP microstructure which leads to intimate interface within the heterojunction and effective charge separation. The recyclability of the AP/LC-2 photocatalysts was evaluated via replicated photocatalytic reaction trials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A mixed solvent (DW:TF) varied strategy used to synthesize Ag<SUB>3</SUB>PO<SUB>4</SUB>/LaCO<SUB>3</SUB>OH (AP/LC) heterostructure photocatalysts. </LI> <LI> A tactic of mixed solvent system helped to tune the morphology, overall properties of AP/LC heterostructures. </LI> <LI> Spherical LC nanoparticles transformed into fine nanowires (in DW:TF=60:40 ratio) to make intimate contact with AP. </LI> <LI> Modified AP/LC heterostructure showed superior photocatalytic efficiency for phenol degradation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>