Chandrashekhar Rode - Academia.edu (original) (raw)

Papers by Chandrashekhar Rode

Research paper thumbnail of A review on non-noble metal catalysts for glycerol hydrodeoxygenation to 1,2-propanediol with and without external hydrogen

Green Chemistry

This review summarizes Cu-based catalysts for sustainable hydro-deoxygenation of glycerol to 1,2-... more This review summarizes Cu-based catalysts for sustainable hydro-deoxygenation of glycerol to 1,2-propanediol with and without external hydrogen including various mechanistic pathways for the reactions involved.

Research paper thumbnail of Continuous Dehydration and Hydrogenolysis of Glycerol over Non-Chromium Copper Catalyst: Laboratory-Scale Process Studies

Organic Process Research & Development, 2012

Research paper thumbnail of Effect of preparation parameters of Cu catalysts on their physico-chemical properties and activities for glycerol hydrogenolysis

Catalysis Today, 2012

Abstract Cu based catalysts were prepared by co-precipitation, alkali fusion followed by precipit... more Abstract Cu based catalysts were prepared by co-precipitation, alkali fusion followed by precipitation and direct solid state fusion methods. The changes in the phase formation, morphology, crystallite size, extent of aggregation, strength and nature of acid sites were observed due to variations in precipitating agents and also their order of addition. The catalyst prepared by co-precipitation using Na 2 CO 3 showed the predominant presence of metallic Cu phase with a crystallite size of 5 nm, well segregated spherical morphology and highest acidity in the activated sample. These intrinsic properties contributed to achieve the highest glycerol conversion of 62% and 1,2-PDO selectivity of 88% in glycerol hydrogenolysis.

Research paper thumbnail of Catalysis for Transforming Biomass to Value Added Chemicals

Although fossil fuels will continue to be the prime energy source for next few years, its limited... more Although fossil fuels will continue to be the prime energy source for next few years, its limited reserves and environmental impact drives us to initiate the transition to renewable and clean energy resources. Among various renewable energy options, biomass occupies a unique position because it is, (i) most abundant and carbon neutral, (ii) acts as energy collector and storage system, (iii) the only large-scale energy source, (iv) available at low capital cost and (v) source of various value added chemicals, befitting to the concept of ‘Biorefinery’. This paper presents a summary of our recent work on catalyst and process development for conversion of biomass derived molecules such as glycerol, levulinic acid and furfural to the respective diols, ring lactones and heterocycles having applications in variety of sectors including fuel and commodity.

Research paper thumbnail of Glucose isomerization to fructose over Ba-Zr mixed metal oxide catalyst

This study investigated various barium mixed metals viz. Zn, Zr, W oxide catalysts for glucose is... more This study investigated various barium mixed metals viz. Zn, Zr, W oxide catalysts for glucose isomerization. The results showed that Ba-Zr (1-1) as most efficient catalyst for glucose isomerisation in terms of 56% glucose conversion and 92% fructose selectivity. Characterization data from XPS, TEM and TPD reveals new insight for the Lewis acid-base assisted glucose isomerization which further illustrates plausible reaction mechanism by structure activity correlation.

Research paper thumbnail of Role of preparation parameters of Cu–Zn mixed oxide catalyst in solvent free glycerol carbonylation with urea

Journal of the Indian Chemical Society

Research paper thumbnail of Bioglycerol ( C3 ) upgrading to 2,3‐butanediol ( C4 ) by cell‐free extracts of Enterobacter aerogenes NCIM 2695

Journal of Chemical Technology & Biotechnology

Research paper thumbnail of Cooperative Acid‐Base Sites of Solid Ba‐Zr Mixed Oxide Catalyst for Efficient Isomerization of Glucose to Fructose in Aqueous Medium

Research paper thumbnail of Correction: Cascade dehydrative amination of glycerol to oxazoline

Catalysis Science & Technology

Correction for ‘Cascade dehydrative amination of glycerol to oxazoline’ by R. Pandya et al., Cata... more Correction for ‘Cascade dehydrative amination of glycerol to oxazoline’ by R. Pandya et al., Catal. Sci. Technol., 2018, 8, 2954–2965, DOI: 10.1039/C8CY00185E.

Research paper thumbnail of A novel process for bioglycerol (C3) upgradation to 2,3-butanediol (C4) by cell free extracts of E. aerogenes NCIM 2695

Production of chemicals from renewable bio-resources is a green and starring approach, which serv... more Production of chemicals from renewable bio-resources is a green and starring approach, which serves as a substitute to petroleum derivatives. Bioglycerol, a C3 triol with its growing production as a co-product of biodiesel, is an attractive low cost feedstock for the synthesis of platform chemicals by microbial fermentation. Upgradation of bioglycerol to C4 diol such as 2,3-butanediol (2,3-BDO) alongwith formation of 1,3-propanediol, acetoin is one of the best alternatives of glycerol value valorization as these products are amongst top biorefinery platform chemicals. Previously, we have reported bioglycerol conversion to 2,3 BDO conversion in 120 h using cell pellets of mixed cultures. While attempting a step closer to “Circular Economy” concept we then focused on utilizing by-product of the process leading to zero waste. Our screening studies showed that cell free extracts of Enterobacter aerogenes NCIM 2695 produced 22 g/L 2,3-BDO from glycerol as a sole source of carbon, within 96 h. Further, glycerol dehydrogenase activity combined with protein analysis depicted cell bound nature. This study offers a faster and effective utilization of cell free extract in the form of supernatant for biocatalysing C3 upgradation to C4 diol which significantly contributes to overall economics of the process using crude glycerol as a sole source of carbon (C3) and serves as an simple, and cost effective fermentative medium.

Research paper thumbnail of Synthesis and characterization of supported heteropoly acid: Efficient solid acid catalyst for glycerol esterification to produce biofuel additives

Inorganic and Nano-Metal Chemistry

Abstract Esterification of glycerol with acetic acid has been studied with different solid acid c... more Abstract Esterification of glycerol with acetic acid has been studied with different solid acid catalysts, prepared by impregnating phospotungustic, silicotungstic, and phosphomolybdic acids on polymeric material polyvinylpyrrolidone. These results were compared with commercially available montmorillonite KSFO catalyst showed that PVP-DTP gave higher selectivity to di- and triacetins. This study was mainly focused on increasing the selectivity toward triacetin which is an excellent alternative to fossil fuel based fuel additives. The detail characterization was done for the PVP-DTP catalyst which gave complete conversion of glycerol and maximum selectivity of 34% toward triacetin. Complete conversion of glycerol was achieved at 110 °C within 6 h of reaction time. The characterization of the catalyst was performed by SEM/EDX, X-ray diffraction, thermogravimetic techniques, and FT-IR analysis.TPD-NH3 characterization showed that DTP supported on PVP increases the catalyst acidity of PVP. The highest acidity of PVP-DTP is also confirmed using NH3-TPD analysis.

Research paper thumbnail of Integration of Heterogeneous Acid and Base Catalysis for Clean Synthesis of Jet‐Fuel Precursor from Carbohydrates

Research paper thumbnail of Fluorescent Carbon-Dots (CDs) Thin Film for Fungal Detection and Bio-labeling Applications

ACS Applied Bio Materials

The fluorescence properties of CDs, such as high quantum yield, tunability of emission color, and... more The fluorescence properties of CDs, such as high quantum yield, tunability of emission color, and so on, make a strong potential material in various fields. These applications are mainly derived from in situ formation of surface functional groups, high chemical stability, biocompatibility, and easy interaction with substrates, etc. Mostly, the research applications of CDs concentrate on the labeling of biological species, drug delivery, and sensing in consequent biomedical applications. However, the detection of the fungal species/spores present in the environment by using CDs is rarely reported. Herein, we demonstrate CDs-based thin film as a sensor for detection of fungal spores from the environment. The procedure of detection is based on fluorescence, observed in the film of carbon dots deposited on quartz plates by using the Blodgett technique. It is observed that the CDs film shows quenching in the fluorescence intensity by the substrate, namely, fungal spores’ (Aspergillus niger, Penicillium chrysog...

Research paper thumbnail of Synthesis of silver nanoparticles colloids in imidazolium halide ionic liquids and their antibacterial activities for gram-positive and gram-negative bacteria

Chemosphere

Four 1-butyl-3-methylimidazolium halide ionic liquids were synthesized via metathesis and anion e... more Four 1-butyl-3-methylimidazolium halide ionic liquids were synthesized via metathesis and anion exchange reactions. Silver nanoparticles (AgNPs) colloids were synthesized in four ionic liquids in the pressurized reactor by reduction of silver nitrate with hydrogen gas, without adding solvents or stabilizing agents. Antibacterial activities of base ionic liquids and AgNPs colloids in ionic liquids were reviewed by well-diffusion method for gram-positive Bacillus cereus (NCIM-2155) and gram-negative Escherichia coli (NCIM-2931) bacteria. Antibacterial activities of ionic liquids and AgNPs colloids in ionic liquids were observed to be controlled by ionic liquids anions and AgNPs particle size. The 1-butyl-3-methylimidazolium iodide ionic liquid exhibited higher antibacterial activities among the studied ionic liquids. Further, the presence of AgNPs in 1-butyl-3-methylimidazolium iodide, ionic liquid enhanced its antibacterial activity for Bacillus cereus and Escherichia coli bacteria.

Research paper thumbnail of Selective hydrogenation of 5-HMF to 2,5-DMF over a magnetically recoverable non-noble metal catalyst

Green Chemistry

A non-noble bimetallic catalyst Cu–Fe (1 : 2) was magnetically recoverable, highly selective and ... more A non-noble bimetallic catalyst Cu–Fe (1 : 2) was magnetically recoverable, highly selective and efficient for 5-(hydroxymethyl) furfural (5-HMF) hydrogenation to 2,5-dimethyl furan (DMF).

Research paper thumbnail of Magnetically separable catalyst for condensation of renewable aldehydes and 2-methylfuran to saturated cyclic oxygenates

Fuel Processing Technology

Abstract The saturated cyclic ethers produced from biomass derived aldehydes and 2-methylfuran ar... more Abstract The saturated cyclic ethers produced from biomass derived aldehydes and 2-methylfuran are the potential diesel fuel candidates. The synthesis of saturated cyclic ethers is a two step process which involves acid catalyzed condensation of aldehydes with 2-methylfuran and the subsequent selective furan ring hydrogenation of the condensation products. Here, we designed a novel recyclable magnetic solid acid catalyst such as [Fe3O4@SiO2-Pr-Py-H][2HSO42−] and employed for the condensation of 2-methylfuran with formaldehyde as model substrates and reaction parameters were optimized. Under the set reaction conditions, condensation of 2-methylfuran with several other aldehydes were also successfully achieved with very good yields. Further, several supported noble metal catalysts were screened in order to find suitable catalyst system for selective furan ring hydrogenation of condensation products. Among those, 5% Pd/C was found to be very active and selective for furan ring hydrogenation without formation of ring opened products under very low hydrogen pressure at room temperature. Prepared catalysts were thoroughly characterized with sophisticated techniques.

Research paper thumbnail of Single-Pot Reductive Rearrangement of Furfural to Cyclopentanone over Silica-Supported Pd Catalysts

ACS Omega

Direct one-pot hydrogenation of furfural (FFR) to cyclopentanone (CPO) was investigated over diff... more Direct one-pot hydrogenation of furfural (FFR) to cyclopentanone (CPO) was investigated over different silica-supported Pd catalysts. Among these, 4% Pd on fumed silica (4%Pd/f-SiO 2) showed remarkable results, achieving almost 98% furfural (FFR) conversion with ∼89% selectivity and 87% yield to cyclopentanone at 165°C and 500 psig H 2 pressure. More interestingly, the fumed-silica-supported catalyst tuned the selectivity toward the rearrangement product, i.e., cyclopentanone, whereas all of the other supports were found to give ring hydrogenation as well as side chain hydrogenation products due to their parent Bronsted acidity and specific support properties. X-ray diffraction data revealed the presence of different phases of the face-centered cubic lattice of metallic Pd along with lowest crystallite size of 15.6 nm in the case of the silica-supported Pd catalyst. However, Pd particle size was found to be in the range of 5−13 nm with even dispersion over the silica support, confirmed by high-resolution transmission electron microscopy analysis. While studying the effect of reaction parameters, it was observed that lower temperature gave low furfural conversion of 58% with only 51% CPO selectivity. Similarly, higher H 2 pressure lowered CPO selectivity with subsequent increase in 2-methyl furan and ring hydrogenation product 2-methyl furan and 2-methyl tetrahydrofuran. Thus, as per the requirement, the product selectivity can be tuned by varying the type of support and/or the reaction parameters suitably. With the help of several control experiments and the characterization data, a plausible reaction pathway was proposed for the selective formation of cyclopentanone.

Research paper thumbnail of Friedel–Crafts Alkylation over Zr-Mont Catalyst for the Production of Diesel Fuel Precursors

ACS Omega

Heterogeneous Zr-Mont catalyst prepared by a simple protocol was employed for the production of d... more Heterogeneous Zr-Mont catalyst prepared by a simple protocol was employed for the production of diesel fuel precursors via Friedel−Crafts (FC) alkylation of petroleumderived arenes (e.g., mesitylene, xylene, and toluene) with biomass-derived 5-(hydroxymethyl)furfural (HMF), HMF derivatives, and carbohydrates. Initially, several acidic catalysts were screened for the FC alkylation of mesitylene with HMF in nitroethane solvent. Among all, Zr-Mont catalyst gave an exceptionally high yield (80%) of mesitylmethylfurfural (MMF). The catalytic activity of Zr-Mont was also evaluated for the alkylation of different petroleum-derived arenes with ester/halogen derivatives of HMF. Suitable acid strength and high surface area of Zr-Mont were its major attributes to make it the most efficient solid acid catalyst for this FC reaction. Even after several reuses, the catalytic activity of Zr-Mont was found to be consistent, which was also evidenced by the acidity measurements of fresh and reused Zr-Mont catalysts by temperature-programmed desorption of ammonia and pyridine Fourier transform infrared spectroscopy techniques. Direct conversion of glucose to diesel fuel precursors was also attempted over Zr-Mont catalyst in mesitylene and polar nonacidic solvents at 150°C. However, the activity of Zr-Mont catalyst was limited for glucose dehydration to HMF and MMF did not form. When the same experiment was performed in formic acid medium, MMF was produced in 34% yield. After the addition of formic acid, the reaction becomes biphasic which contains mesitylene as an organic phase and formic acid as an aqueous phase. Formic acid worked as a solvent, reactant, and cocatalyst, whereas mesitylene worked as a reactant and product extraction phase to enable easy product isolation. With this strategy, other diesel fuel precursors were also produced in 26−30% yields from glucose and different arenes. Similar strategy was successfully extended for the conversion of sucrose to diesel fuel precursors.

Research paper thumbnail of Crystalline LaCoO3 perovskite as a novel catalyst for glycerol transesterification

Molecular Catalysis

Abstract LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors... more Abstract LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors of La and Co with varying molar ratios of La and Co (1:1, 1:2 and 2:1). This was found to be an unique strategy to obtain highly crystalline LaCoO3 perovskite material without using any chelating agent. The variation of precursors was found to influence their crystallinity however, variation in molar ratio in the range of 0.5–2, did not affect the formation of perovskite framework. The formation of pure perovskite phase (around or >80%) could be achieved by combination of acetate and nitrate precursors while, the combination of acetate- acetate or nitrate- nitrate precursors resulted in low phase purity for the perovskite due to the formation of secondary phases like La2O3 and Co3O4. Very interestingly, such combination of perovskite and pure oxide phases contributed to enhancement of basic sites which catalyzed the glycerol transestrifiaction with DMC (dimethyl carbonate) to GC (glycerol carbonate) and GD (glycidol). Among all the catalysts studied, NAP-2 showed highest efficiency in terms of 98% glycerol conversion and 77% GC and 22% GD selectivities. The highlight of this work is that first step glycerol transesterification with DMC required basic sites of either metal oxide or perovskite but for cascade reaction involving decarboxylation required both metal oxide as well as LaCoO3 perovskite phase.

Research paper thumbnail of Cascade dehydrative amination of glycerol to oxazoline

Catalysis Science & Technology

A method for the direct conversion of bioglycerol to oxazoline was devised involving glycerol deh... more A method for the direct conversion of bioglycerol to oxazoline was devised involving glycerol dehydration to acetol followed by its amination with aqueous ammonia.

Research paper thumbnail of A review on non-noble metal catalysts for glycerol hydrodeoxygenation to 1,2-propanediol with and without external hydrogen

Green Chemistry

This review summarizes Cu-based catalysts for sustainable hydro-deoxygenation of glycerol to 1,2-... more This review summarizes Cu-based catalysts for sustainable hydro-deoxygenation of glycerol to 1,2-propanediol with and without external hydrogen including various mechanistic pathways for the reactions involved.

Research paper thumbnail of Continuous Dehydration and Hydrogenolysis of Glycerol over Non-Chromium Copper Catalyst: Laboratory-Scale Process Studies

Organic Process Research & Development, 2012

Research paper thumbnail of Effect of preparation parameters of Cu catalysts on their physico-chemical properties and activities for glycerol hydrogenolysis

Catalysis Today, 2012

Abstract Cu based catalysts were prepared by co-precipitation, alkali fusion followed by precipit... more Abstract Cu based catalysts were prepared by co-precipitation, alkali fusion followed by precipitation and direct solid state fusion methods. The changes in the phase formation, morphology, crystallite size, extent of aggregation, strength and nature of acid sites were observed due to variations in precipitating agents and also their order of addition. The catalyst prepared by co-precipitation using Na 2 CO 3 showed the predominant presence of metallic Cu phase with a crystallite size of 5 nm, well segregated spherical morphology and highest acidity in the activated sample. These intrinsic properties contributed to achieve the highest glycerol conversion of 62% and 1,2-PDO selectivity of 88% in glycerol hydrogenolysis.

Research paper thumbnail of Catalysis for Transforming Biomass to Value Added Chemicals

Although fossil fuels will continue to be the prime energy source for next few years, its limited... more Although fossil fuels will continue to be the prime energy source for next few years, its limited reserves and environmental impact drives us to initiate the transition to renewable and clean energy resources. Among various renewable energy options, biomass occupies a unique position because it is, (i) most abundant and carbon neutral, (ii) acts as energy collector and storage system, (iii) the only large-scale energy source, (iv) available at low capital cost and (v) source of various value added chemicals, befitting to the concept of ‘Biorefinery’. This paper presents a summary of our recent work on catalyst and process development for conversion of biomass derived molecules such as glycerol, levulinic acid and furfural to the respective diols, ring lactones and heterocycles having applications in variety of sectors including fuel and commodity.

Research paper thumbnail of Glucose isomerization to fructose over Ba-Zr mixed metal oxide catalyst

This study investigated various barium mixed metals viz. Zn, Zr, W oxide catalysts for glucose is... more This study investigated various barium mixed metals viz. Zn, Zr, W oxide catalysts for glucose isomerization. The results showed that Ba-Zr (1-1) as most efficient catalyst for glucose isomerisation in terms of 56% glucose conversion and 92% fructose selectivity. Characterization data from XPS, TEM and TPD reveals new insight for the Lewis acid-base assisted glucose isomerization which further illustrates plausible reaction mechanism by structure activity correlation.

Research paper thumbnail of Role of preparation parameters of Cu–Zn mixed oxide catalyst in solvent free glycerol carbonylation with urea

Journal of the Indian Chemical Society

Research paper thumbnail of Bioglycerol ( C3 ) upgrading to 2,3‐butanediol ( C4 ) by cell‐free extracts of Enterobacter aerogenes NCIM 2695

Journal of Chemical Technology & Biotechnology

Research paper thumbnail of Cooperative Acid‐Base Sites of Solid Ba‐Zr Mixed Oxide Catalyst for Efficient Isomerization of Glucose to Fructose in Aqueous Medium

Research paper thumbnail of Correction: Cascade dehydrative amination of glycerol to oxazoline

Catalysis Science & Technology

Correction for ‘Cascade dehydrative amination of glycerol to oxazoline’ by R. Pandya et al., Cata... more Correction for ‘Cascade dehydrative amination of glycerol to oxazoline’ by R. Pandya et al., Catal. Sci. Technol., 2018, 8, 2954–2965, DOI: 10.1039/C8CY00185E.

Research paper thumbnail of A novel process for bioglycerol (C3) upgradation to 2,3-butanediol (C4) by cell free extracts of E. aerogenes NCIM 2695

Production of chemicals from renewable bio-resources is a green and starring approach, which serv... more Production of chemicals from renewable bio-resources is a green and starring approach, which serves as a substitute to petroleum derivatives. Bioglycerol, a C3 triol with its growing production as a co-product of biodiesel, is an attractive low cost feedstock for the synthesis of platform chemicals by microbial fermentation. Upgradation of bioglycerol to C4 diol such as 2,3-butanediol (2,3-BDO) alongwith formation of 1,3-propanediol, acetoin is one of the best alternatives of glycerol value valorization as these products are amongst top biorefinery platform chemicals. Previously, we have reported bioglycerol conversion to 2,3 BDO conversion in 120 h using cell pellets of mixed cultures. While attempting a step closer to “Circular Economy” concept we then focused on utilizing by-product of the process leading to zero waste. Our screening studies showed that cell free extracts of Enterobacter aerogenes NCIM 2695 produced 22 g/L 2,3-BDO from glycerol as a sole source of carbon, within 96 h. Further, glycerol dehydrogenase activity combined with protein analysis depicted cell bound nature. This study offers a faster and effective utilization of cell free extract in the form of supernatant for biocatalysing C3 upgradation to C4 diol which significantly contributes to overall economics of the process using crude glycerol as a sole source of carbon (C3) and serves as an simple, and cost effective fermentative medium.

Research paper thumbnail of Synthesis and characterization of supported heteropoly acid: Efficient solid acid catalyst for glycerol esterification to produce biofuel additives

Inorganic and Nano-Metal Chemistry

Abstract Esterification of glycerol with acetic acid has been studied with different solid acid c... more Abstract Esterification of glycerol with acetic acid has been studied with different solid acid catalysts, prepared by impregnating phospotungustic, silicotungstic, and phosphomolybdic acids on polymeric material polyvinylpyrrolidone. These results were compared with commercially available montmorillonite KSFO catalyst showed that PVP-DTP gave higher selectivity to di- and triacetins. This study was mainly focused on increasing the selectivity toward triacetin which is an excellent alternative to fossil fuel based fuel additives. The detail characterization was done for the PVP-DTP catalyst which gave complete conversion of glycerol and maximum selectivity of 34% toward triacetin. Complete conversion of glycerol was achieved at 110 °C within 6 h of reaction time. The characterization of the catalyst was performed by SEM/EDX, X-ray diffraction, thermogravimetic techniques, and FT-IR analysis.TPD-NH3 characterization showed that DTP supported on PVP increases the catalyst acidity of PVP. The highest acidity of PVP-DTP is also confirmed using NH3-TPD analysis.

Research paper thumbnail of Integration of Heterogeneous Acid and Base Catalysis for Clean Synthesis of Jet‐Fuel Precursor from Carbohydrates

Research paper thumbnail of Fluorescent Carbon-Dots (CDs) Thin Film for Fungal Detection and Bio-labeling Applications

ACS Applied Bio Materials

The fluorescence properties of CDs, such as high quantum yield, tunability of emission color, and... more The fluorescence properties of CDs, such as high quantum yield, tunability of emission color, and so on, make a strong potential material in various fields. These applications are mainly derived from in situ formation of surface functional groups, high chemical stability, biocompatibility, and easy interaction with substrates, etc. Mostly, the research applications of CDs concentrate on the labeling of biological species, drug delivery, and sensing in consequent biomedical applications. However, the detection of the fungal species/spores present in the environment by using CDs is rarely reported. Herein, we demonstrate CDs-based thin film as a sensor for detection of fungal spores from the environment. The procedure of detection is based on fluorescence, observed in the film of carbon dots deposited on quartz plates by using the Blodgett technique. It is observed that the CDs film shows quenching in the fluorescence intensity by the substrate, namely, fungal spores’ (Aspergillus niger, Penicillium chrysog...

Research paper thumbnail of Synthesis of silver nanoparticles colloids in imidazolium halide ionic liquids and their antibacterial activities for gram-positive and gram-negative bacteria

Chemosphere

Four 1-butyl-3-methylimidazolium halide ionic liquids were synthesized via metathesis and anion e... more Four 1-butyl-3-methylimidazolium halide ionic liquids were synthesized via metathesis and anion exchange reactions. Silver nanoparticles (AgNPs) colloids were synthesized in four ionic liquids in the pressurized reactor by reduction of silver nitrate with hydrogen gas, without adding solvents or stabilizing agents. Antibacterial activities of base ionic liquids and AgNPs colloids in ionic liquids were reviewed by well-diffusion method for gram-positive Bacillus cereus (NCIM-2155) and gram-negative Escherichia coli (NCIM-2931) bacteria. Antibacterial activities of ionic liquids and AgNPs colloids in ionic liquids were observed to be controlled by ionic liquids anions and AgNPs particle size. The 1-butyl-3-methylimidazolium iodide ionic liquid exhibited higher antibacterial activities among the studied ionic liquids. Further, the presence of AgNPs in 1-butyl-3-methylimidazolium iodide, ionic liquid enhanced its antibacterial activity for Bacillus cereus and Escherichia coli bacteria.

Research paper thumbnail of Selective hydrogenation of 5-HMF to 2,5-DMF over a magnetically recoverable non-noble metal catalyst

Green Chemistry

A non-noble bimetallic catalyst Cu–Fe (1 : 2) was magnetically recoverable, highly selective and ... more A non-noble bimetallic catalyst Cu–Fe (1 : 2) was magnetically recoverable, highly selective and efficient for 5-(hydroxymethyl) furfural (5-HMF) hydrogenation to 2,5-dimethyl furan (DMF).

Research paper thumbnail of Magnetically separable catalyst for condensation of renewable aldehydes and 2-methylfuran to saturated cyclic oxygenates

Fuel Processing Technology

Abstract The saturated cyclic ethers produced from biomass derived aldehydes and 2-methylfuran ar... more Abstract The saturated cyclic ethers produced from biomass derived aldehydes and 2-methylfuran are the potential diesel fuel candidates. The synthesis of saturated cyclic ethers is a two step process which involves acid catalyzed condensation of aldehydes with 2-methylfuran and the subsequent selective furan ring hydrogenation of the condensation products. Here, we designed a novel recyclable magnetic solid acid catalyst such as [Fe3O4@SiO2-Pr-Py-H][2HSO42−] and employed for the condensation of 2-methylfuran with formaldehyde as model substrates and reaction parameters were optimized. Under the set reaction conditions, condensation of 2-methylfuran with several other aldehydes were also successfully achieved with very good yields. Further, several supported noble metal catalysts were screened in order to find suitable catalyst system for selective furan ring hydrogenation of condensation products. Among those, 5% Pd/C was found to be very active and selective for furan ring hydrogenation without formation of ring opened products under very low hydrogen pressure at room temperature. Prepared catalysts were thoroughly characterized with sophisticated techniques.

Research paper thumbnail of Single-Pot Reductive Rearrangement of Furfural to Cyclopentanone over Silica-Supported Pd Catalysts

ACS Omega

Direct one-pot hydrogenation of furfural (FFR) to cyclopentanone (CPO) was investigated over diff... more Direct one-pot hydrogenation of furfural (FFR) to cyclopentanone (CPO) was investigated over different silica-supported Pd catalysts. Among these, 4% Pd on fumed silica (4%Pd/f-SiO 2) showed remarkable results, achieving almost 98% furfural (FFR) conversion with ∼89% selectivity and 87% yield to cyclopentanone at 165°C and 500 psig H 2 pressure. More interestingly, the fumed-silica-supported catalyst tuned the selectivity toward the rearrangement product, i.e., cyclopentanone, whereas all of the other supports were found to give ring hydrogenation as well as side chain hydrogenation products due to their parent Bronsted acidity and specific support properties. X-ray diffraction data revealed the presence of different phases of the face-centered cubic lattice of metallic Pd along with lowest crystallite size of 15.6 nm in the case of the silica-supported Pd catalyst. However, Pd particle size was found to be in the range of 5−13 nm with even dispersion over the silica support, confirmed by high-resolution transmission electron microscopy analysis. While studying the effect of reaction parameters, it was observed that lower temperature gave low furfural conversion of 58% with only 51% CPO selectivity. Similarly, higher H 2 pressure lowered CPO selectivity with subsequent increase in 2-methyl furan and ring hydrogenation product 2-methyl furan and 2-methyl tetrahydrofuran. Thus, as per the requirement, the product selectivity can be tuned by varying the type of support and/or the reaction parameters suitably. With the help of several control experiments and the characterization data, a plausible reaction pathway was proposed for the selective formation of cyclopentanone.

Research paper thumbnail of Friedel–Crafts Alkylation over Zr-Mont Catalyst for the Production of Diesel Fuel Precursors

ACS Omega

Heterogeneous Zr-Mont catalyst prepared by a simple protocol was employed for the production of d... more Heterogeneous Zr-Mont catalyst prepared by a simple protocol was employed for the production of diesel fuel precursors via Friedel−Crafts (FC) alkylation of petroleumderived arenes (e.g., mesitylene, xylene, and toluene) with biomass-derived 5-(hydroxymethyl)furfural (HMF), HMF derivatives, and carbohydrates. Initially, several acidic catalysts were screened for the FC alkylation of mesitylene with HMF in nitroethane solvent. Among all, Zr-Mont catalyst gave an exceptionally high yield (80%) of mesitylmethylfurfural (MMF). The catalytic activity of Zr-Mont was also evaluated for the alkylation of different petroleum-derived arenes with ester/halogen derivatives of HMF. Suitable acid strength and high surface area of Zr-Mont were its major attributes to make it the most efficient solid acid catalyst for this FC reaction. Even after several reuses, the catalytic activity of Zr-Mont was found to be consistent, which was also evidenced by the acidity measurements of fresh and reused Zr-Mont catalysts by temperature-programmed desorption of ammonia and pyridine Fourier transform infrared spectroscopy techniques. Direct conversion of glucose to diesel fuel precursors was also attempted over Zr-Mont catalyst in mesitylene and polar nonacidic solvents at 150°C. However, the activity of Zr-Mont catalyst was limited for glucose dehydration to HMF and MMF did not form. When the same experiment was performed in formic acid medium, MMF was produced in 34% yield. After the addition of formic acid, the reaction becomes biphasic which contains mesitylene as an organic phase and formic acid as an aqueous phase. Formic acid worked as a solvent, reactant, and cocatalyst, whereas mesitylene worked as a reactant and product extraction phase to enable easy product isolation. With this strategy, other diesel fuel precursors were also produced in 26−30% yields from glucose and different arenes. Similar strategy was successfully extended for the conversion of sucrose to diesel fuel precursors.

Research paper thumbnail of Crystalline LaCoO3 perovskite as a novel catalyst for glycerol transesterification

Molecular Catalysis

Abstract LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors... more Abstract LaCoO3 perovskite was synthesized using sol-gel method by nitrate and acetate precursors of La and Co with varying molar ratios of La and Co (1:1, 1:2 and 2:1). This was found to be an unique strategy to obtain highly crystalline LaCoO3 perovskite material without using any chelating agent. The variation of precursors was found to influence their crystallinity however, variation in molar ratio in the range of 0.5–2, did not affect the formation of perovskite framework. The formation of pure perovskite phase (around or >80%) could be achieved by combination of acetate and nitrate precursors while, the combination of acetate- acetate or nitrate- nitrate precursors resulted in low phase purity for the perovskite due to the formation of secondary phases like La2O3 and Co3O4. Very interestingly, such combination of perovskite and pure oxide phases contributed to enhancement of basic sites which catalyzed the glycerol transestrifiaction with DMC (dimethyl carbonate) to GC (glycerol carbonate) and GD (glycidol). Among all the catalysts studied, NAP-2 showed highest efficiency in terms of 98% glycerol conversion and 77% GC and 22% GD selectivities. The highlight of this work is that first step glycerol transesterification with DMC required basic sites of either metal oxide or perovskite but for cascade reaction involving decarboxylation required both metal oxide as well as LaCoO3 perovskite phase.

Research paper thumbnail of Cascade dehydrative amination of glycerol to oxazoline

Catalysis Science & Technology

A method for the direct conversion of bioglycerol to oxazoline was devised involving glycerol deh... more A method for the direct conversion of bioglycerol to oxazoline was devised involving glycerol dehydration to acetol followed by its amination with aqueous ammonia.