A Novel Mesoporous Silica-Grafted Organocatalyst for the Michael Addition Reaction, Synthesized v... more A Novel Mesoporous Silica-Grafted Organocatalyst for the Michael Addition Reaction, Synthesized via the Click Method.-The efficient and recyclable bifunctional acid-base catalyst for the Michael addition of ketones to β-nitrostyrenes presented here affords the corresponding products with excellent stereoselectivity and in good to excellent yields.-(JAIN*,
Hg(ii) contamination in water is a major health issue. Functionalized organic materials have huge... more Hg(ii) contamination in water is a major health issue. Functionalized organic materials have huge scope for the large-scale adsorptive removal of Hg(ii). This review summarizes major achievements of POPs and COFs in the water purification purposes.
Al-free Sn-silicalites with MFI, MEL and MTW structures have been synthesizedhydrothermally and c... more Al-free Sn-silicalites with MFI, MEL and MTW structures have been synthesizedhydrothermally and characterized by XRD, FT-IR, 119 Sn MAS-NMR and sorption techniques. The unit cell volume expansion depends on the manner Sn atoms are linked to the silicalite network. ...
New mesoporous titanium-phosphorus mixed oxides templated by non-ionic triblock copolymer Pluroni... more New mesoporous titanium-phosphorus mixed oxides templated by non-ionic triblock copolymer Pluronic F127 under evaporation induced self-assembly (EISA) method and using unconventional phosphorus source trimethylphosphite have been reported. Powder XRD, TEM and N 2 sorption studies are employed to characterize the mesophases. TPD-NH 3 experiments suggested an increase in surface acidity with the increase in the molar ratio of Ti/P in these mesoporous mixed oxides from 1 to 2. Interestingly these mesoporous materials showed excellent bifunctional catalytic activity in acid catalyzed Friedel-Crafts benzylation of bulky aromatics and partial oxidation of styrene to benzaldehyde with dilute H 2 O 2 oxidant under mild liquid phase conditions.
New wormhole-like mesoporous TiO(2) material has been synthesized through a convenient sol-gel me... more New wormhole-like mesoporous TiO(2) material has been synthesized through a convenient sol-gel method in the presence of a Schiff base secondary amine hexadecyl-2-pyrrole-methylamine (HPMA) containing chelating donor sites as template or structure directing agent (SDA). SDA molecules can be easily removed from the composite to generate mesoporosity and upon removal of the SDA molecule, this mesoporous TiO(2) material showed very high surface area (480+/-10 m(2)/g) with an average pore diameter of 2.57+/-0.05 nm. When Rose Bengal dye is entrapped inside the nanopores of this material, it showed a drastic enhancement (ca. 40-folds) in the photoconductivity vis-à-vis mesoporous TiO(2) alone under white light illumination.
Abstract Mesoporous Sn-SBA-15 has been synthesized by three different methods such as conventiona... more Abstract Mesoporous Sn-SBA-15 has been synthesized by three different methods such as conventional hydrothermal route, using cocatalyst NH4F and in the presence of organosilane precursor. All the materials are thoroughly characterized by powder X-ray diffraction (XRD), SEM, TEM, N2 sorption and surface area measurements, diffuse-reflectance UV–visible and FTIR spectroscopy, TG–DTA and elemental analysis through ICP. Nitrogen adsorption data, XRD patterns, and TEM observations suggests that the textural properties are retained during the isomorphous substitution of silicon by tin. ICP chemical analysis indicates that tin can be substituted in the range of Si/Sn = 69–162. UV–visible spectra of samples synthesized by the cocatalytic approach exhibit unique absorption band at 213 nm characteristics of tin atom substituted in the smaller pores (2–3 nm) located inside the walls of mesopores. Further, an additional band at 224 nm can be assigned to Sn atoms located in the distorted tetrahedral position along the primary mesopores. In contrary, only one absorption band centered at 224 nm is observed for all the samples synthesized by conventional hydrothermal as well as in the presence of organosilane precursor. 19F NMR spectra confirmed (no signal) the absence of occluded F− ions in the samples made with NH4F. Observed high catalytic activity in Baeyer–Villiger oxidation and Meerwin–Pondorf–Verly reduction under the liquid-phase conditions suggest the incorporation of a portion of tin in the smaller pores for the Sn-SBA-15 materials synthesized through cocatalyst method.
A new zinc phosphonate catalyst for the synthesis of tetra-cyclic carbonates, carbamates and poly... more A new zinc phosphonate catalyst for the synthesis of tetra-cyclic carbonates, carbamates and polyurethanes using CO2 as C1 source is reported.
The development of an efficient, sustainable, and inexpensive metal-free catalyst for oxygen evol... more The development of an efficient, sustainable, and inexpensive metal-free catalyst for oxygen evolution reaction (OER) via photoelectrochemical water splitting is very demanding for energy conversion processes such as green fuel generators, fuel cells, and metal-air batteries. Herein, we have developed a metal-free pyrene-based nitrogen and sulfur containing conjugated microporous polymer having a high Brunauer-Emmett-Teller surface area (761 m2 g−1) and a low bandgap of 2.09 eV for oxygen evolution reaction (OER) in alkaline solution. The π-conjugated as-synthesized porous organic material (PBTDZ) has been characterized by Fourier transform infrared spectroscopy (FT-IR), solid-state 13C (cross-polarization magic angle spinning-nuclear magnetic resonance) CP-MAS NMR, N2 adsorption/desorption analysis, field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA...
Catalytic reduction of CO2 is very challenging from both economics and green chemistry perspectiv... more Catalytic reduction of CO2 is very challenging from both economics and green chemistry perspectives. This critical review highlights major advancements made in the CO2 reduction processes and their future challenges.
Solid acid catalysts occupy a special class in heterogeneous catalysis for their efficiency in ec... more Solid acid catalysts occupy a special class in heterogeneous catalysis for their efficiency in eco-friendly conversion of biomass into demanding chemicals. We synthesized porphyrin containing porous organic polymers (PorPOPs) using colloidal silica as a support. Post-modification with chlorosulfonic acid enabled sulfonic acid functionalization, and the resulting material (PorPOPS) showed excellent activity and durability for the conversion of fructose to 5-hydroxymethyl furfural (HMF) in green solvent water. PorPOPS composite was characterized by N2 sorption, FTIR, TGA, CHNS, FESEM, TEM and XPS techniques, justifying the successful synthesis of organic networks and the grafting of sulfonic acid sites (5 wt%). Furthermore, a high surface area (260 m2/g) and the presence of distinct mesopores of ~15 nm were distinctly different from the porphyrin containing sulfonated porous organic polymer (FePOP-1S). Surprisingly the hybrid PorPOPS showed an excellent yield of HMF (85%) and high sel...
We report a new N- and S-rich highly ordered periodic mesoporous organosilica material DMTZ-PMO b... more We report a new N- and S-rich highly ordered periodic mesoporous organosilica material DMTZ-PMO bearing thiadiazole and thiol moieties inside the pore-wall for very efficient and fast removal of Hg2+ from polluted water (uptake = 2081 mg g−1).
A new Fe-MOF prepared by using a tetraphosphonic acid as a ligand is reported and it showed high ... more A new Fe-MOF prepared by using a tetraphosphonic acid as a ligand is reported and it showed high specific capacity and excellent recycling efficiency in lithium-ion batteries.
Abstract Hexagonally ordered mesoporous silica material SBA-15 with thick pore wall is an ideal c... more Abstract Hexagonally ordered mesoporous silica material SBA-15 with thick pore wall is an ideal catalytic support for immobilizing reactive tiny metal oxide nanoparticles (NPs) due to its large pore size, high specific surface area, excellent feasibility for the immobilization of NPs and robust nature of the mesoporous framework. NiO@SBA-15 nanocomposite material has been synthesised through non-ionic surfactant assisted hydrothermal synthesis of SBA-15 followed by calcination, functionalization and impregnation. The material has been thoroughly characterized by using powder XRD, N2 sorption, XPS and NH3-TPD. NiO@SBA-15 with ca. 13 % Ni(II) loading displayed specific surface area of 409 m2 g−1 and weak surface acidity. NiO@SBA-15 showed good catalytic activity for conversion of ethanol to hydrocarbon fuels, specifically C1 and C4 hydrocarbons at 300 C together with the production of hydrogen in almost stoichiometric amount. Further increase in the reaction temperature favoured cracking to yield methane as the major product. Supported NiO NPs acts as efficient catalytic centre for the conversion of ethanol to hydrocarbon fuels, which is an alternate to fossil fuel. Catalytic process is environment friendly and sustainable as the feedstock ethanol can be easily obtained from biomass resources.
To overcome the challenges of global warming and environmental pollution it is mandatory to reduc... more To overcome the challenges of global warming and environmental pollution it is mandatory to reduce the concentration of atmospheric carbon dioxide (CO2), which is largely accumulated in air through the combustion of fossil fuels. Thus, sequestration of CO2 through physisorption on solid adsorbents and their successful conversion into value added fine chemicals are the major priority areas of research today. Innovation of efficient solid CO2‐philic adsorbents together with their high mechanical/chemical stability and regeneration efficiency are the most challenging objectives to achieve this goal. In this context, porous organic polymers (POPs) owing to their high specific surface area, chemical stability, nanoscale porosity and structural diversity have huge potential to play as selective CO2 adsorbent. POPs synthesized through large varieties of reactive monomers via simple and convenient chemical routes can be the ideal adsorbents for the CO2 storage and fixation reactions. A wide...
A Novel Mesoporous Silica-Grafted Organocatalyst for the Michael Addition Reaction, Synthesized v... more A Novel Mesoporous Silica-Grafted Organocatalyst for the Michael Addition Reaction, Synthesized via the Click Method.-The efficient and recyclable bifunctional acid-base catalyst for the Michael addition of ketones to β-nitrostyrenes presented here affords the corresponding products with excellent stereoselectivity and in good to excellent yields.-(JAIN*,
Hg(ii) contamination in water is a major health issue. Functionalized organic materials have huge... more Hg(ii) contamination in water is a major health issue. Functionalized organic materials have huge scope for the large-scale adsorptive removal of Hg(ii). This review summarizes major achievements of POPs and COFs in the water purification purposes.
Al-free Sn-silicalites with MFI, MEL and MTW structures have been synthesizedhydrothermally and c... more Al-free Sn-silicalites with MFI, MEL and MTW structures have been synthesizedhydrothermally and characterized by XRD, FT-IR, 119 Sn MAS-NMR and sorption techniques. The unit cell volume expansion depends on the manner Sn atoms are linked to the silicalite network. ...
New mesoporous titanium-phosphorus mixed oxides templated by non-ionic triblock copolymer Pluroni... more New mesoporous titanium-phosphorus mixed oxides templated by non-ionic triblock copolymer Pluronic F127 under evaporation induced self-assembly (EISA) method and using unconventional phosphorus source trimethylphosphite have been reported. Powder XRD, TEM and N 2 sorption studies are employed to characterize the mesophases. TPD-NH 3 experiments suggested an increase in surface acidity with the increase in the molar ratio of Ti/P in these mesoporous mixed oxides from 1 to 2. Interestingly these mesoporous materials showed excellent bifunctional catalytic activity in acid catalyzed Friedel-Crafts benzylation of bulky aromatics and partial oxidation of styrene to benzaldehyde with dilute H 2 O 2 oxidant under mild liquid phase conditions.
New wormhole-like mesoporous TiO(2) material has been synthesized through a convenient sol-gel me... more New wormhole-like mesoporous TiO(2) material has been synthesized through a convenient sol-gel method in the presence of a Schiff base secondary amine hexadecyl-2-pyrrole-methylamine (HPMA) containing chelating donor sites as template or structure directing agent (SDA). SDA molecules can be easily removed from the composite to generate mesoporosity and upon removal of the SDA molecule, this mesoporous TiO(2) material showed very high surface area (480+/-10 m(2)/g) with an average pore diameter of 2.57+/-0.05 nm. When Rose Bengal dye is entrapped inside the nanopores of this material, it showed a drastic enhancement (ca. 40-folds) in the photoconductivity vis-à-vis mesoporous TiO(2) alone under white light illumination.
Abstract Mesoporous Sn-SBA-15 has been synthesized by three different methods such as conventiona... more Abstract Mesoporous Sn-SBA-15 has been synthesized by three different methods such as conventional hydrothermal route, using cocatalyst NH4F and in the presence of organosilane precursor. All the materials are thoroughly characterized by powder X-ray diffraction (XRD), SEM, TEM, N2 sorption and surface area measurements, diffuse-reflectance UV–visible and FTIR spectroscopy, TG–DTA and elemental analysis through ICP. Nitrogen adsorption data, XRD patterns, and TEM observations suggests that the textural properties are retained during the isomorphous substitution of silicon by tin. ICP chemical analysis indicates that tin can be substituted in the range of Si/Sn = 69–162. UV–visible spectra of samples synthesized by the cocatalytic approach exhibit unique absorption band at 213 nm characteristics of tin atom substituted in the smaller pores (2–3 nm) located inside the walls of mesopores. Further, an additional band at 224 nm can be assigned to Sn atoms located in the distorted tetrahedral position along the primary mesopores. In contrary, only one absorption band centered at 224 nm is observed for all the samples synthesized by conventional hydrothermal as well as in the presence of organosilane precursor. 19F NMR spectra confirmed (no signal) the absence of occluded F− ions in the samples made with NH4F. Observed high catalytic activity in Baeyer–Villiger oxidation and Meerwin–Pondorf–Verly reduction under the liquid-phase conditions suggest the incorporation of a portion of tin in the smaller pores for the Sn-SBA-15 materials synthesized through cocatalyst method.
A new zinc phosphonate catalyst for the synthesis of tetra-cyclic carbonates, carbamates and poly... more A new zinc phosphonate catalyst for the synthesis of tetra-cyclic carbonates, carbamates and polyurethanes using CO2 as C1 source is reported.
The development of an efficient, sustainable, and inexpensive metal-free catalyst for oxygen evol... more The development of an efficient, sustainable, and inexpensive metal-free catalyst for oxygen evolution reaction (OER) via photoelectrochemical water splitting is very demanding for energy conversion processes such as green fuel generators, fuel cells, and metal-air batteries. Herein, we have developed a metal-free pyrene-based nitrogen and sulfur containing conjugated microporous polymer having a high Brunauer-Emmett-Teller surface area (761 m2 g−1) and a low bandgap of 2.09 eV for oxygen evolution reaction (OER) in alkaline solution. The π-conjugated as-synthesized porous organic material (PBTDZ) has been characterized by Fourier transform infrared spectroscopy (FT-IR), solid-state 13C (cross-polarization magic angle spinning-nuclear magnetic resonance) CP-MAS NMR, N2 adsorption/desorption analysis, field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA...
Catalytic reduction of CO2 is very challenging from both economics and green chemistry perspectiv... more Catalytic reduction of CO2 is very challenging from both economics and green chemistry perspectives. This critical review highlights major advancements made in the CO2 reduction processes and their future challenges.
Solid acid catalysts occupy a special class in heterogeneous catalysis for their efficiency in ec... more Solid acid catalysts occupy a special class in heterogeneous catalysis for their efficiency in eco-friendly conversion of biomass into demanding chemicals. We synthesized porphyrin containing porous organic polymers (PorPOPs) using colloidal silica as a support. Post-modification with chlorosulfonic acid enabled sulfonic acid functionalization, and the resulting material (PorPOPS) showed excellent activity and durability for the conversion of fructose to 5-hydroxymethyl furfural (HMF) in green solvent water. PorPOPS composite was characterized by N2 sorption, FTIR, TGA, CHNS, FESEM, TEM and XPS techniques, justifying the successful synthesis of organic networks and the grafting of sulfonic acid sites (5 wt%). Furthermore, a high surface area (260 m2/g) and the presence of distinct mesopores of ~15 nm were distinctly different from the porphyrin containing sulfonated porous organic polymer (FePOP-1S). Surprisingly the hybrid PorPOPS showed an excellent yield of HMF (85%) and high sel...
We report a new N- and S-rich highly ordered periodic mesoporous organosilica material DMTZ-PMO b... more We report a new N- and S-rich highly ordered periodic mesoporous organosilica material DMTZ-PMO bearing thiadiazole and thiol moieties inside the pore-wall for very efficient and fast removal of Hg2+ from polluted water (uptake = 2081 mg g−1).
A new Fe-MOF prepared by using a tetraphosphonic acid as a ligand is reported and it showed high ... more A new Fe-MOF prepared by using a tetraphosphonic acid as a ligand is reported and it showed high specific capacity and excellent recycling efficiency in lithium-ion batteries.
Abstract Hexagonally ordered mesoporous silica material SBA-15 with thick pore wall is an ideal c... more Abstract Hexagonally ordered mesoporous silica material SBA-15 with thick pore wall is an ideal catalytic support for immobilizing reactive tiny metal oxide nanoparticles (NPs) due to its large pore size, high specific surface area, excellent feasibility for the immobilization of NPs and robust nature of the mesoporous framework. NiO@SBA-15 nanocomposite material has been synthesised through non-ionic surfactant assisted hydrothermal synthesis of SBA-15 followed by calcination, functionalization and impregnation. The material has been thoroughly characterized by using powder XRD, N2 sorption, XPS and NH3-TPD. NiO@SBA-15 with ca. 13 % Ni(II) loading displayed specific surface area of 409 m2 g−1 and weak surface acidity. NiO@SBA-15 showed good catalytic activity for conversion of ethanol to hydrocarbon fuels, specifically C1 and C4 hydrocarbons at 300 C together with the production of hydrogen in almost stoichiometric amount. Further increase in the reaction temperature favoured cracking to yield methane as the major product. Supported NiO NPs acts as efficient catalytic centre for the conversion of ethanol to hydrocarbon fuels, which is an alternate to fossil fuel. Catalytic process is environment friendly and sustainable as the feedstock ethanol can be easily obtained from biomass resources.
To overcome the challenges of global warming and environmental pollution it is mandatory to reduc... more To overcome the challenges of global warming and environmental pollution it is mandatory to reduce the concentration of atmospheric carbon dioxide (CO2), which is largely accumulated in air through the combustion of fossil fuels. Thus, sequestration of CO2 through physisorption on solid adsorbents and their successful conversion into value added fine chemicals are the major priority areas of research today. Innovation of efficient solid CO2‐philic adsorbents together with their high mechanical/chemical stability and regeneration efficiency are the most challenging objectives to achieve this goal. In this context, porous organic polymers (POPs) owing to their high specific surface area, chemical stability, nanoscale porosity and structural diversity have huge potential to play as selective CO2 adsorbent. POPs synthesized through large varieties of reactive monomers via simple and convenient chemical routes can be the ideal adsorbents for the CO2 storage and fixation reactions. A wide...
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