Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade... more
Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed.
Research Interests:
Decreasing fossil fuel resources has forced the mankind to explore alternative sources to make up the gap between energy demand and its production. Lignocellulosic biomass is currently considered as one of the best solutions for this... more
Decreasing fossil fuel resources has forced the mankind to explore alternative sources to make up the gap between energy demand and its production. Lignocellulosic biomass is currently considered as one of the best solutions for this consequence, since it is highly abundant and has no competition with food crops. This chapter discloses some efficient catalytic approaches for the conversion of lignocellulose feedstocks into liquid hydrocarbon fuels via deoxygenation processes. Different catalytic factors of nanomaterials including composition, functionalities, and effect of catalyst support in the deoxygenation process are critically discussed.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Benzimidazole derivatives have attracted a significant attention in recent years because of their medicinal applications as antiviral, antiulcer, antifungal, antihypertensive, anticancer, and antihistamine compounds. The one-pot... more
ABSTRACT Benzimidazole derivatives have attracted a significant attention in recent years because of their medicinal applications as antiviral, antiulcer, antifungal, antihypertensive, anticancer, and antihistamine compounds. The one-pot synthesis of benzimidazole derivatives via oxidative condensation of aromatic aldehydes with o-phenylenediamines under mild conditions was successfully accomplished using a cobalt(II) supported on mesoporous silica-type material. The supported cobalt catalyst could be easily recovered after reaction completion and reused seven times with an excellent durability and without any noticeable loss in activity. Graphical Abstract
Research Interests:
Research Interests: Materials Science, Chemistry, Catalysis, Nanomaterials, Nanotechnology, and 14 moreMedicine, Heterogeneous Catalysis, Mechanochemistry, Metal Organic Frameworks, Nanostructures, In situ, Real Time, CHEMICAL SCIENCES, Zeolitic Imidazolate Frameworks, Solvent free synthesis (Green Chemistry), Visible Light, Mechanical Processes, Chemical Engineering Communications, and Gold catalysts
Research Interests:
Research Interests:
The current review article summarizes the recent advances of SACs in the biomass conversion process. A detailed and fundamental discussion is made from the aspects of unique activity, reaction mechanism, and industrial implications of SACs.
Research Interests:
The current review article summarizes the recent advances of SACs in the biomass conversion process. A detailed and fundamental discussion is made from the aspects of unique activity, reaction mechanism, and industrial implications of SACs.
Research Interests:
ABSTRACT Recent approaches to furfural synthesis from hemicellulosic biomass and pentose sugars with both homogeneous and solid acidic catalysts have been summarized by addressing the associated sustainability issues. The features of... more
ABSTRACT Recent approaches to furfural synthesis from hemicellulosic biomass and pentose sugars with both homogeneous and solid acidic catalysts have been summarized by addressing the associated sustainability issues. The features of deconstruction of hemicellulosic biomass by acid hydrolysis to produce pentose sugar feedstock for furfural have been discussed in brief. Several strategies including solvent extraction in a biphasic process, application of surface functionalized materials such as acidic resins, mesoporous solids and mechanistic insight in limited cases are discussed. The present status of the promising furfural platform in producing second generation biofuels (furanics and hydrocarbon) is reviewed. The performances of each catalytic system are assessed in terms of intrinsic reactivity and selectivity toward furfural production. Overall, this minireview attempts to highlight the scope of further developments for a sustainable furfural process and upgrading to fuels.
Research Interests:
Research Interests:
Research Interests:
Utilization of CO2 as feedstock to produce fine chemicals and renewable fuels is a highly promising field, which presents unique challenges in its implementation at scale. Heterogeneous catalysis w...
Research Interests:
Research Interests:
Research Interests:
High acidity titanium phosphate (TiP) material was synthesized by a reaction between commercial TiO2 and H3PO4 under reflux condition. The synthesized material was characterized by FTIR, XRD and TEM; a probable formula was derived by... more
High acidity titanium phosphate (TiP) material was synthesized by a reaction between commercial TiO2 and H3PO4 under reflux condition. The synthesized material was characterized by FTIR, XRD and TEM; a probable formula was derived by thermogravimetric, elemental and XRD analysis. NH3-TPD measurement confirmed the exceptional high acidity of the material. The catalytic efficiency of the TiP material was tested against the dehydration of various sugars for the production of an important building block molecule, 5-hydroxymethylfurfural (HMF) in a biphasic water/THF solvent system. The Lewis and Brønsted acidic nature of TiP material helps the isomerisation of glucose to fructose followed by an excellent conversion into HMF. Good recyclability of the catalyst can be attributed to its high stability and water-tolerant acidic properties.
Research Interests:
Decreasing fossil fuel resources has forced the mankind to explore alternative sources to make up the gap between energy demand and its production. Lignocellulosic biomass is currently considered as one of the best solutions for this... more
Decreasing fossil fuel resources has forced the mankind to explore alternative sources to make up the gap between energy demand and its production. Lignocellulosic biomass is currently considered as one of the best solutions for this consequence, since it is highly abundant and has no competition with food crops. This chapter discloses some efficient catalytic approaches for the conversion of lignocellulose feedstocks into liquid hydrocarbon fuels via deoxygenation processes. Different catalytic factors of nanomaterials including composition, functionalities, and effect of catalyst support in the deoxygenation process are critically discussed.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT Benzimidazole derivatives have attracted a significant attention in recent years because of their medicinal applications as antiviral, antiulcer, antifungal, antihypertensive, anticancer, and antihistamine compounds. The one-pot... more
ABSTRACT Benzimidazole derivatives have attracted a significant attention in recent years because of their medicinal applications as antiviral, antiulcer, antifungal, antihypertensive, anticancer, and antihistamine compounds. The one-pot synthesis of benzimidazole derivatives via oxidative condensation of aromatic aldehydes with o-phenylenediamines under mild conditions was successfully accomplished using a cobalt(II) supported on mesoporous silica-type material. The supported cobalt catalyst could be easily recovered after reaction completion and reused seven times with an excellent durability and without any noticeable loss in activity. Graphical Abstract
Research Interests:
Novel biomass‐derived porous carbons are attractive candidates for the preparation of carbon‐supported catalysts with a wide range of catalytic applications. Such carbonaceous catalysts are environmentally benign and could provide a... more
Novel biomass‐derived porous carbons are attractive candidates for the preparation of carbon‐supported catalysts with a wide range of catalytic applications. Such carbonaceous catalysts are environmentally benign and could provide a cost‐competitive advantage as compared to existing heterogeneous catalysts. Tunable surface properties of carbon materials and excellent physical properties (e.g., hydrophobicity, chemically inert nature, etc.) are compatible with diverse catalysis reactions including organic transformations, as well as electro‐ and photochemical processes in aqueous solutions. This contribution provides an overview on the utilization of different biomass feedstocks and/or biomass‐derived precursors for the synthesis of carbonaceous materials to design advanced catalytic systems and their emerging applications in catalysis.
Research Interests:
Research Interests:
Research Interests:
Recent approaches to furfural synthesis from hemicellulosic biomass and pentose sugars with both homogeneous and solid acidic catalysts have been summarized by addressing the associated sustainability issues. The features of... more
Recent approaches to furfural synthesis from hemicellulosic biomass and pentose sugars with both homogeneous and solid acidic catalysts have been summarized by addressing the associated sustainability issues. The features of deconstruction of hemicellulosic biomass by acid hydrolysis to produce pentose sugar feedstock for furfural have been discussed in brief. Several strategies including solvent extraction in a biphasic process, application of surface functionalized materials such as acidic resins, mesoporous solids and mechanistic insight in limited cases are discussed. The present status of the promising furfural platform in producing second generation biofuels (furanics and hydrocarbon) is reviewed. The performances of each catalytic system are assessed in terms of intrinsic reactivity and selectivity toward furfural production. Overall, this minireview attempts to highlight the scope of further developments for a sustainable furfural process and upgrading to fuels.
Research Interests:
Research Interests:
ABSTRACT The synthesis of fine chemicals from the platform molecules obtained through the degradation of the cellulosic and lignocellulosic biomass is a most widely envisioned approach toward the implementation of renewable feedstocks for... more
ABSTRACT The synthesis of fine chemicals from the platform molecules obtained through the degradation of the cellulosic and lignocellulosic biomass is a most widely envisioned approach toward the implementation of renewable feedstocks for fuels and chemicals. Significant advances have been made in the synthesis of furan-based polyester building block 2,5-furandicarboxylic acid (FDCA) and related compounds such as 2,5-bis(hydroxymethyl)furan and 2,5-bis(hydroxymethyl)tetrahydrofuran from biomass-derived 5-hydroxymethylfurfural (HMF) by using homogeneous and nanoparticulate catalysts. This review provides a survey of selective aerobic oxidation of HMF to give FDCA as the end-product. The article highlights the fundamental aspects of preferring nanoparticulate catalysts over the conventional supported metal catalysts for the synthesis of FDCA with high selectivity. Another objective of the review is to discuss how efficiently the HMF-platform produces biofuels, including gasoline blendstock 2,5-dimethylfuran (DMF), 5-ethoxymethylfurfural (EMF), and ethyl levulinate (EL), which are competitive of existing liquid fuels.
Research Interests:
Conversion of glycerol to cyclic acetals and to mono-, di- and triacetylglycerides was investigated using a supported iron oxide nanoparticle system of a mesoporous aluminosilicate heterogeneous catalyst (Fe/Al-SBA-15).
Research Interests:
We have synthesized a furan-based acetylating agent, 2,5-bisacetoxymethylfuran (BAMF) from carbohydrate derived 5-hydroxymethylfurfural (HMF) and studied its acetylation activity with amines and cytochrome c. The results show that BAMF... more
We have synthesized a furan-based acetylating agent, 2,5-bisacetoxymethylfuran (BAMF) from carbohydrate derived 5-hydroxymethylfurfural (HMF) and studied its acetylation activity with amines and cytochrome c. The results show that BAMF can modify proteins in biological conditions without affecting their structure and function. The modification of cytochrome c with BAMF occurred through the reduction of heme center, but there was no change in the coordination property of iron and the tertiary structure of cytochrome c. Further analysis using MALDI-TOF-MS spectrometer suggests that BAMF selectively targeted lysine amino acid of cytochrome c under our experimental conditions. Kinetics study revealed that the modification of cytochrome c with BAMF took place at faster rates than aspirin.
Research Interests:
ABSTRACT The catalytic activity of Lewis acidic metal chlorides were screened for the production of biofuel precursor platform chemical, 5-hydroxymethylfurfural (HMF), from carbohydrates and biopolymers in aqueous and biphasic solvents... more
ABSTRACT The catalytic activity of Lewis acidic metal chlorides were screened for the production of biofuel precursor platform chemical, 5-hydroxymethylfurfural (HMF), from carbohydrates and biopolymers in aqueous and biphasic solvents under microwave and conventional heating methods. The screening of metal chloride catalysts for dehydration of several carbohydrate substrates revealed that Zr(O)Cl2 catalyst is the most effective. Cheap and readily abundant Zr(O)Cl2 catalyst produced 63% and 42% HMF from fructose and glucose, respectively, in water using methylisobutylketone (MIBK) as the organic phase in biphasic solvent system. The yield of HMF increased to 84% and 66% when Zr(O)Cl2 catalyzed dehydration of fructose and glucose was carried out in [BMIM]Cl (1-butyl-3-methylimidazolium chloride)-MIBK biphasic solvent. 1H NMR studies revealed that the dehydration reactions progressed through the formation of fructofuranose as an intermediate. Accordingly, a mechanism for isomerization of glucopyranose to fructofuranose has been proposed. The catalyst was recycled for five catalytic cycles without a significant loss in its activity.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
The review is devoted exclusively to the catalyst development and engineering approaches for the one-pot transformation of benzene to aniline. The authors begin with a brief description of the present industrial methods of aniline... more
The review is devoted exclusively to the catalyst development and engineering approaches for the one-pot transformation of benzene to aniline. The authors begin with a brief description of the present industrial methods of aniline production and its potential drawbacks regarding the economics and environmental issues. This comprehensive review has been categorized into several sections based on the nature of the catalysts, catalysts preparations and characterizations, their performance and optimizations for aniline yields and selectivity, nature of the aminating agents, and nature of the oxidative agents. Special emphasis has been given to the M/MO cataloreactants, metal redox catalysts, and mesoporous crystalline materials.
Research Interests:
Nano-scale metal particles have huge potential due to their wide range of diverse catalytic applications. Recently, they have found numerous applications in the field of biomass conversion. The proposed contribution is aimed at providing... more
Nano-scale metal particles have huge potential due to their wide range of diverse catalytic applications. Recently, they have found numerous applications in the field of biomass conversion. The proposed contribution is aimed at providing a brief account of remarkable recent findings and advances in the design of metal-based nanocatalysts for biomass valorization. We have discussed the rational control of the size, shape, composition and surface properties of nano-scale metal catalysts. Following that, the interplay between various structural parameters and the catalytic properties in the transformation of cellulose, chitin, lignin and lipids has been critically discussed.
Research Interests:
Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting... more
Vanillin is one of the most commonly used natural products, which can also be produced from lignin-derived feedstocks. The chemical synthesis of vanillin is well-established in large-scale production from petrochemical-based starting materials. To overcome this problem, lignin-derived monomers (such as eugenol, isoeugenol, ferulic acid etc.) have been effectively used in the past few years. However, selective and efficient production of vanillin from these feedstocks still remains an issue to replace the existing process. In this work, new transition metal-based catalysts were proposed to investigate their efficiency in vanillin production. Reduced graphene oxide supported Fe and Co catalysts showed high conversion of isoeugenol under mild reaction conditions using H2O2 as oxidizing agent. Fe catalysts were more selective as compared to Co catalysts, providing a 63% vanillin selectivity at 61% conversion in 2 h. The mechanochemical process was demonstrated as an effective approach t...