scholarly journals Metal-Free Heptazine-Based Porous Polymeric Network as Highly Efficient Catalyst for CO2 Capture and Conversion

2021 ◽  
Vol 9 ◽  
Author(s):  
Neha Sharma ◽  
Bharat Ugale ◽  
Sunil Kumar ◽  
Kamalakannan Kailasam
Keyword(s):  
Rational Design ◽  
Structural Integrity ◽  
Cycloaddition Reaction ◽  
Value Added ◽  
Cyclic Carbonate ◽  
Energy Crisis ◽  
Water Stability ◽  
High Chemical ◽  
Efficient Catalyst ◽  
Microporous Polymer

The capture and catalytic conversion of CO2 into value-added chemicals is a promising and sustainable approach to tackle the global warming and energy crisis. The nitrogen-rich porous organic polymers are excellent materials for CO2 capture and separation. Herein, we present a nitrogen-rich heptazine-based microporous polymer for the cycloaddition reaction of CO2 with epoxides in the absence of metals and solvents. HMP-TAPA, being rich in the nitrogen site, showed a high CO2 uptake of 106.7 mg/g with an IAST selectivity of 30.79 toward CO2 over N2. Furthermore, HMP-TAPA showed high chemical and water stability without loss of any structural integrity. Besides CO2 sorption, the catalytic activity of HMP-TAPA was checked for the cycloaddition of CO2 and terminal epoxides, resulting in cyclic carbonate with high conversion (98%). They showed remarkable recyclability up to 5 cycles without loss of activity. Overall, this study represents a rare demonstration of the rational design of POPs (HMP-TAPA) for multiple applications.

scholarly journals Enhanced Catalysis through Structurally Modified Hybrid 2-D Boron Nitride Nanosheets Comprising of Complexed 2-hydroxy-4- methoxybenzophenone Motif

2021 ◽  
Author(s):  
Pooja Rana ◽  
Ranjana Dixit ◽  
Shivani Sharma ◽  
Sriparna Dutta ◽  
Sneha Yadav ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Rational Design ◽  
Surface Engineering ◽  
Structural Integrity ◽  
Hexagonal Boron Nitride ◽  
Cycloaddition Reaction ◽  
Rational Surface ◽  
Organic Transformations ◽  
Hybrid Nanomaterial ◽  
Catalytic Potential

Abstract Tuning the scturtrual architecture of the pristine two dimensional hexagonal boron nitride (h-BN) nanosheets through rational surface engineering can prove advantageous in the fabrication of competent catalytic materials. Inspired by the performance of h-BN based nanomaterials in expediting key organic transformations, we channelized our research efforts towards engineering the inherent surface properties of the exclusively stacked h-BN through the incorporation of a novel competent copper complex of a bidentate chelating ligand 2-hydroxy-4-methoxybenzophenone. Delightfully, this hybrid nanomaterial worked exceptionally well in boosting the [3+2] cycloaddition reaction of azide and nitriles, providing a facile access to a diverse variety of highly bioactive tetrazole motifs. A deep insight into the morphology of the covalently crafted h-BN signified the structural integrity of the exfoliated h-BN@OH nanosheets that exhibited lamellar like structures possessing smooth edges and flat surface. This interesting morphology could also be envisioned to augment the catalysis by allowing the desired surface area for the reactants and thus tailoring their activity. The work paves the way towards rational design of h-BN based nanomaterials and adjusting their catalytic potential by the use of suitable complexes for promoting sustainable catalysis, especially in view of the fact that till date only a very few h-BN nanosheets based catalysts have been devised.

scholarly journals Enhanced catalysis through structurally modified hybrid 2-D boron nitride nanosheets comprising of complexed 2-hydroxy-4-methoxybenzophenone motif

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pooja Rana ◽  
Ranjana Dixit ◽  
Shivani Sharma ◽  
Sriparna Dutta ◽  
Sneha Yadav ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Rational Design ◽  
Surface Engineering ◽  
Structural Integrity ◽  
Hexagonal Boron Nitride ◽  
Cycloaddition Reaction ◽  
Rational Surface ◽  
Hybrid Nanomaterial ◽  
Catalytic Potential ◽  
Structural Architecture

AbstractTuning the structural architecture of the pristine two dimensional hexagonal boron nitride (h-BN) nanosheets through rational surface engineering have proven advantageous in the fabrication of competent catalytic materials. Inspired by the performance of h-BN based nanomaterials in expediting key organic transformations, we channelized our research efforts towards engineering the inherent surface properties of the exclusively stacked h-BN nanosheets through the incorporation of a novel competent copper complex of a bidentate chelating ligand 2-hydroxy-4-methoxybenzophenone (BP). Delightfully, this hybrid nanomaterial worked exceptionally well in boosting the [3 + 2] cycloaddition reaction of azide and nitriles, providing a facile access to a diverse variety of highly bioactive tetrazole motifs. A deep insight into the morphology of the covalently crafted h-BN signified the structural integrity of the exfoliated h-BN@OH nanosheets that exhibited lamellar like structures possessing smooth edges and flat surface. This interesting morphology could also be envisioned to augment the catalysis by allowing the desired surface area for the reactants and thus tailoring their activity. The work paves the way towards rational design of h-BN based nanomaterials and adjusting their catalytic potential by the use of suitable complexes for promoting sustainable catalysis, especially in view of the fact that till date only a very few h-BN nanosheets based catalysts have been devised.

scholarly journals Zn 1,3,5-benzenetricarboxylate as an efficient catalyst for the synthesis of cyclic carbonates from CO2

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9192-9201 ◽  
Author(s):  
Chao Feng ◽  
Xianglei Cao ◽  
Liugen Zhang ◽  
Changyan Guo ◽  
Naeem Akram ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Cycloaddition Reaction ◽  
Cyclic Carbonate ◽  
Solvent Free ◽  
Cyclic Carbonates ◽  
Efficient Catalyst ◽  
Solvent Free Conditions

[Zn3(BTC)2], a heterogeneous catalyst, can efficiently catalyze the cycloaddition reaction. Under relatively moderate and solvent-free conditions, the yield of cyclic carbonate reached 99%.

scholarly journals Highly Efficient MOF Catalyst Systems for CO2 Conversion to Bis-Cyclic Carbonates as Building Blocks for NIPHUs (Non-Isocyanate Polyhydroxyurethanes) Synthesis

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 628
Author(s):  
Adolfo Benedito ◽  
Eider Acarreta ◽  
Enrique Giménez
Keyword(s):  
Molar Mass ◽  
Cycloaddition Reaction ◽  
Building Blocks ◽  
Catalyst System ◽  
Cyclic Carbonate ◽  
Ammonium Bromide ◽  
Cyclic Carbonates ◽  
High Molar Mass ◽  
Highly Efficient ◽  
Free Process

The present paper describes a greener sustainable route toward the synthesis of NIPHUs. We report a highly efficient solvent-free process to produce [4,4′-bi(1,3-dioxolane)]-2,2′-dione (BDC), involving CO2, as renewable feedstock, and bis-epoxide (1,3-butadiendiepoxide) using only metal–organic frameworks (MOFs) as catalysts and cetyltrimethyl-ammonium bromide (CTAB) as a co-catalyst. This synthetic procedure is evaluated in the context of reducing global emissions of waste CO2 and converting CO2 into useful chemical feedstocks. The reaction was carried out in a pressurized reactor at pressures of 30 bars and controlled temperatures of around 120–130 °C. This study examines how reaction parameters such as catalyst used, temperature, or reaction time can influence the molar mass, yield, or reactivity of BDC. High BDC reactivity is essential for producing high molar mass linear non-isocyanate polyhydroxyurethane (NIPHU) via melt-phase polyaddition with aliphatic diamines. The optimized Al-OH-fumarate catalyst system described in this paper exhibited a 78% GC-MS conversion for the desired cyclic carbonates, in the absence of a solvent and a 50 wt % chemically fixed CO2. The cycloaddition reaction could also be carried out in the absence of CTAB, although lower cyclic carbonate yields were observed.

scholarly journals Computational-Driven Epitope Verification and Affinity Maturation of TLR4-Targeting Antibodies

2021 ◽  
Vol 22 (11) ◽  
pp. 5989
Author(s):  
Bilal Ahmad ◽  
Maria Batool ◽  
Moon Suk Kim ◽  
Sangdun Choi
Keyword(s):  
Rational Design ◽  
Structural Integrity ◽  
Critical Role ◽  
Autoimmune Encephalitis ◽  
Affinity Maturation ◽  
Antibody Binding ◽  
Computational Techniques ◽  
Multiple Strategies ◽  
Binding Epitope

Toll-like receptor (TLR) signaling plays a critical role in the induction and progression of autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematous, experimental autoimmune encephalitis, type 1 diabetes mellitus and neurodegenerative diseases. Deciphering antigen recognition by antibodies provides insights and defines the mechanism of action into the progression of immune responses. Multiple strategies, including phage display and hybridoma technologies, have been used to enhance the affinity of antibodies for their respective epitopes. Here, we investigate the TLR4 antibody-binding epitope by computational-driven approach. We demonstrate that three important residues, i.e., Y328, N329, and K349 of TLR4 antibody binding epitope identified upon in silico mutagenesis, affect not only the interaction and binding affinity of antibody but also influence the structural integrity of TLR4. Furthermore, we predict a novel epitope at the TLR4-MD2 interface which can be targeted and explored for therapeutic antibodies and small molecules. This technique provides an in-depth insight into antibody–antigen interactions at the resolution and will be beneficial for the development of new monoclonal antibodies. Computational techniques, if coupled with experimental methods, will shorten the duration of rational design and development of antibody therapeutics.

Aliphatic Carboxylic Acid as Hydrogen-Bond Donor for Converting CO2 and Epoxide into Cyclic Carbonate under Mild Conditions

2021 ◽  
Author(s):  
Zheng Wang ◽  
Yajun Wang ◽  
Qianjie Xie ◽  
Zhiying Fan ◽  
Yehua Shen
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Value Added ◽  
Cyclic Carbonate ◽  
Hydrogen Bond Donor ◽  
Title Reaction ◽  
Aliphatic Carboxylic Acid ◽  
Mild Conditions ◽  
Atmospheric Carbon

The coupling of CO2 and epoxide is promising way to reduce atmospheric carbon by converting it into value-added cyclic carbonate. Pursuing efficient catalysts is highly attractive for the title reaction....

scholarly journals Enhancing the thermostability and activity of uronate dehydrogenase from Agrobacterium tumefaciens LBA4404 by semi-rational engineering

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Hui-Hui Su ◽  
Fei Peng ◽  
Pei Xu ◽  
Xiao-Ling Wu ◽  
Min-Hua Zong ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Rational Design ◽  
Glucuronic Acid ◽  
Specific Activity ◽  
Value Added ◽  
Catalytic Efficiency ◽  
Site Directed Mutagenesis ◽  
Glucaric Acid ◽  
Triple Mutant ◽  
Pharmaceutical Industries

Abstract Background Glucaric acid, one of the aldaric acids, has been declared a “top value-added chemical from biomass”, and is especially important in the food and pharmaceutical industries. Biocatalytic production of glucaric acid from glucuronic acid is more environmentally friendly, efficient and economical than chemical synthesis. Uronate dehydrogenases (UDHs) are the key enzymes for the preparation of glucaric acid in this way, but the poor thermostability and low activity of UDH limit its industrial application. Therefore, improving the thermostability and activity of UDH, for example by semi-rational design, is a major research goal. Results In the present work, three UDHs were obtained from different Agrobacterium tumefaciens strains. The three UDHs have an approximate molecular weight of 32 kDa and all contain typically conserved UDH motifs. All three UDHs showed optimal activity within a pH range of 6.0–8.5 and at a temperature of 30 °C, but the UDH from A. tumefaciens (At) LBA4404 had a better catalytic efficiency than the other two UDHs (800 vs 600 and 530 s−1 mM−1). To further boost the catalytic performance of the UDH from AtLBA4404, site-directed mutagenesis based on semi-rational design was carried out. An A39P/H99Y/H234K triple mutant showed a 400-fold improvement in half-life at 59 °C, a 5 °C improvement in $$ {\text{T}}_{ 5 0}^{ 1 0} $$ T 50 10 value and a 2.5-fold improvement in specific activity at 30 °C compared to wild-type UDH. Conclusions In this study, we successfully obtained a triple mutant (A39P/H99Y/H234K) with simultaneously enhanced activity and thermostability, which provides a novel alternative for the industrial production of glucaric acid from glucuronic acid.

Fluorine Doping Assisted Vacancy Engineering for Efficient Electrocatalyst towards Hydrogen Production

2021 ◽  
Author(s):  
Xinhong Chen ◽  
Mengjiao Wei ◽  
Jia Zhou
Keyword(s):  
Hydrogen Production ◽  
Rational Design ◽  
Energy Crisis ◽  
Fluorine Doping

The rational design of an efficient and stable electrocatalyst utilizing defects plays a key role in promoting hydrogen production from electrolytic water to tackle the energy crisis. In this work,...

scholarly journals Green Pathway in Utilizing CO2 via Cycloaddition Reaction with Epoxide—A Mini Review

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 548 ◽  
Author(s):  
Kunlanan Kiatkittipong ◽  
Muhammad Amirul Amin Mohamad Shukri ◽  
Worapon Kiatkittipong ◽  
Jun Wei Lim ◽  
Pau Loke Show ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Metal Organic Framework ◽  
Sustainable Use ◽  
Cycloaddition Reaction ◽  
Cyclic Carbonate ◽  
Organic Salt ◽  
Catalytic Systems ◽  
Carbonate Production ◽  
Use Of Resources ◽  
Salen Complexes

Carbon dioxide (CO2) has been anticipated as an ideal carbon building block for organic synthesis due to the noble properties of CO2, which are abundant renewable carbon feedstock, non-toxic nature, and contributing to a more sustainable use of resources. Several green and proficient routes have been established for chemical CO2 fixation. Among the prominent routes, this review epitomizes the reactions involving cycloaddition of epoxides with CO2 in producing cyclic carbonate. Cyclic carbonate has been widely used as a polar aprotic solvent, as an electrolyte in Li-ion batteries, and as precursors for various forms of chemical synthesis such as polycarbonates and polyurethanes. This review provides an overview in terms of the reaction mechanistic pathway and recent advances in the development of several classes of catalysts, including homogeneous organocatalysts (e.g., organic salt, ionic liquid, deep eutectic solvents), organometallic (e.g., mono-, bi-, and tri-metal salen complexes and non-salen complexes) and heterogeneous supported catalysts, and metal organic framework (MOF). Selection of effective catalysts for various epoxide substrates is very important in determining the cycloaddition operating condition. Under their catalytic systems, all classes of these catalysts, with regard to recent developments, can exhibit CO2 cycloaddition of terminal epoxide substrates at ambient temperatures and low CO2 pressure. Although highly desired conversion can be achieved for internal epoxide substrates, higher temperature and pressure are normally required. This includes fatty acid-derived terminal epoxides for oleochemical carbonate production. The production of fully renewable resources by employment of bio-based epoxy with biorefinery concept and potential enhancement of cycloaddition reactions are pointed out as well.

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