@article {48271, title = {Hydrogenation of levulinic acid to gamma-valerolactone over nickel supported organoclay catalyst}, journal = {Catalysis Today}, volume = {408}, year = {2023}, month = {JAN }, pages = {36-49}, type = {Article}, abstract = {

In this work, a series of Ni/Organoclay catalysts with different Nickel loadings were prepared by the wetimpregnation method for the catalytic hydrogenation of levulinic acid (LA) to gamma-valerolactone (GVL). Reaction parameters such as reaction temperature, pressure, solvent effect, and wt\% of catalyst were optimized to get excellent conversion of levulinic acid selectively to gamma-valerolactone. Ni/Organoclay with 30\% Nickel loading exhibited 100\% conversion of LA with 100\% selectivity towards GVL at 140 degrees C and 3.0 MPa H2 pressure using 1,4-dioxane as a solvent in 5 h. Different bulk and surface characterization techniques such as XRD, BET, FE-SEM, HR-TEM, XPS, XRF, NH3-TPD, and H2-Chemisorption were used to characterize the Ni/Organoclay catalyst. BET and NH3-TPD analysis showed that the pre-treatment of bentonite with surfactant (CTAB) improved the pore volume, surface area, and acidity of Organoclay which assisted in improving the conversion and selectivity of LA and GVL respectively.

}, keywords = {?-Valerolactone (GVL), Bentonite, Hydrogenation, Levulinic acid (LA), Nickel, organoclay}, issn = {0920-5861}, doi = {10.1016/j.cattod.2022.10.004}, author = {Kamble, Paresh A. and Vinod, C. P. and Rathod, Virendra K. and Kantam, Mannepalli Lakshmi} } @article {48458, title = {Imine oxidation catalyzed by zinc hydroxyapatite: kinetic studies}, journal = {ChemistrySelect}, volume = {8}, year = {2023}, month = {MAY}, pages = {e202203503}, type = {Article}, abstract = {

The synthesis of N,N-diphenylformamide from N-benzylideneaniline and urea hydrogen peroxide is investigated using a zinc hydroxyapatite (ZnHAP) catalyst. It was found that the catalyst resulted in the highest activity of 91 \% conversion and 40 \% selectivity at 130 degrees C in 2 h. A kinetic model was validated by Langmuir-Hinshelwood-Hougen-Watson (LHHW) at different temperatures and the absence of mass transfer resistance was proved by the Weisz Prater criterion. Effect of different catalysts, catalyst loading, temperature, mole-ratio, and speed of stirring was studied. The as-synthesized catalyst is characterized by FTIR, BET nitrogen adsorption-desorption, TEM, EDX, TPD-NH3, XPS, ICP-MS and XRD. ZnHAP catalyst was found to be stable up to three recycles with no loss in activity.

}, keywords = {heterogeneous catalysis, hydroxyapatite, imines, Oxidation, Reaction kinetics}, issn = {2365-6549}, doi = {10.1002/slct.202203503}, author = {Vishwakarma, Rakhi and Vinod, C. P. and Rathod, Virendra K. and Kantam, Mannepalli Lakshmi} } @article {48491, title = {Wadsworth-emmons reaction by using the fluorapatite catalyst: kinetic studies}, journal = {Industrial \& Engineering Chemistry Research}, volume = {62}, year = {2023}, month = {MAY }, pages = {7901-7911}, type = {Article}, abstract = {

Wadsworth-Emmons reaction was successfully carriedout byusing the fluorapatite (FAP) catalyst. The reaction of 2-methoxybenzaldehydeand triethylphosphonoacetate using FAP afforded \& alpha;,\& beta;-unsaturatedester with 100\% conversion and 80\% selectivity. A kinetic model wasvalidated at different temperatures by Langmuir-Hinshelwood-Hougen-Watson(LHHW), and the absence of mass transfer resistance was verified bythe Weisz Prater criterion. The effect of different catalysts, temperature,catalyst loading, solvent, mole ratio, and speed of stirring was studied.The FAP catalyst was characterized by Fourier transform infrared spectroscopy,Brunauer-Emmett-Teller method, nitrogen adsorption-desorption,transmission electron microscopy, energy-dispersive X-ray spectroscopy,temperature programmed desorption (TPD-NH3), X-ray diffraction,and X-ray photoelectron spectroscopy. The FAP catalyst was found tobe stable up to three recycles with no loss in activity.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.3c00407}, author = {Vishwakarma, Rakhi and Vinod, Chathakudath P. and Rathod, Virendra and Kantam, Mannepalli Lakshmi} } @article {49084, title = {Hydrogenation of furfural to tetrahydrofurfuryl alcohol over nickel-supported on organoclay catalyst}, journal = {Applied Catalysis A-General}, volume = {674}, year = {2024}, month = {MAR }, pages = {119621}, type = {Article}, abstract = {

Nickel supported on organoclay prepared by the impregnation method provides excellent catalytic activity for the hydrogenation of furfural to tetrahydrofurfuryl alcohol. The relative amount of metal and acidic sites influences the hydrogenation reaction. Additionally, by varying the temperature and the H-2 pressure, we can regulate the interaction of furfural with the active sites. And this may decide the fate of the reaction whether it will undergo a two-step hydrogenation to form tetrahydrofurfuryl alcohol or a rearrangement reaction to form cyclopentanone/cyclopentanol. Water was found to be the best solvent for the selective formation of tetrahydrofurfuryl alcohol. Even though alcohols inhibited rearrangement reaction, the hydrogenation of furfural was more selective towards furfuryl alcohol. Ni/O-clay30A under the optimum conditions of 120 degrees C, 4.0 MPa, and in 1 h offered complete conversion of furfural to tetrahydrofurfuryl alcohol.

}, keywords = {furfural, Hydrogenation, Nickel, organoclay, Tetrahydrofurfuryl alcohol}, issn = {0926-860X}, doi = {10.1016/j.apcata.2024.119621}, author = {Kamble, Paresh A. and Vinod, C. P. and Rathod, Virendra K. and Kantam, Mannepalli Lakshmi} } @article {49050, title = {Kinetic model of hydrogenation of glucose to sorbitol on a Ni/Bentonite catalyst}, journal = {Industrial and Engineering Chemistry Research}, volume = {63}, year = {2024}, month = {MAR }, pages = {4771-4781}, type = {Article}, abstract = {

In the present work, we studied the hydrogenation of glucose to sorbitol using a nickel/bentonite catalyst. The Ni/bentonite catalyst was prepared by the wet impregnation method and characterized by different methods to understand the catalyst surface morphology, surface area, metal content, pore size, etc. Different reaction parameters such as temperature, hydrogen pressure, metal loading, catalyst loading, and agitation speed were studied to achieve a glucose conversion of 96.8\% and a sorbitol selectivity of 95.3\%. The reusability test was performed to examine the stability of the catalyst. The kinetic models such as the Eley-Rideal and Langmuir-Hinshelwood-Hougen-Watson models were used to study the hydrogenation of glucose and activation energy required for the reaction.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.3c03808}, author = {Pandya, Harmitkumar and Vinod, Chathakudath Prabhakaran and Rathod, Virendra and Kantam, Mannepalli Lakshmi} } @article {49858, title = {Aldol Condensation of Furfural with Acetone by Using Mg-Al-O-t-Bu HT Catalyst and Kinetic Studies}, journal = {Industrial \& Engineering Chemistry Research}, volume = {64}, year = {2025}, month = {DEC}, pages = {24938-24948}, type = {Article}, abstract = {

An environment-friendly method for producing jet fuel precursors involves the aldol condensation of biomass-derived chemicals. In this study, the condensation reaction between furfural and acetone was performed using a Mg-Al-O-t-Bu hydrotalcite (HT) catalyst, achieving a furfural conversion of 99\% and a selectivity of 82\% toward 4-(2-furyl)-3-buten-2-one (FAc). The kinetics of the process were evaluated using a Langmuir-Hinshelwood-Hougen-Watson (LHHW) model across a range of temperatures, and the model showed an excellent fit to the experimental data. The effect of different catalysts, reaction temperatures, catalyst loadings, molar ratios, and reaction times was systematically investigated. The Mg-Al-O-t-Bu HT catalyst was extensively analyzed through techniques such as XRD, XPS, FTIR, nitrogen adsorption-desorption measurements, and CO2-TPD. The catalyst exhibited excellent stability, maintaining its performance consistently across five successive reaction cycles with no notable decline in activity. These findings highlight the industrial relevance of Mg-Al-O-t-Bu HT as a robust and recyclable solid base catalyst for biomass upgrading, with strong potential for process scale-up in renewable fuel production.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.5c03287}, author = {Patil, Sneha and Kamble, Paresh and Vinod, Chathakudath Prabhakaran and Rathod, Virendra and Kantam, Mannepalli Lakshmi} } @article {49856, title = {Synthesis of 5-hydroxymethylfurfural from glucose using a tert-butoxyapatite catalyst}, journal = {DALTON TRANSACTIONS}, volume = {54}, year = {2025}, month = {SEP}, pages = {13574-13587}, type = {Article}, abstract = {

In this study, 5-hydroxymethylfurfural (5-HMF) was obtained from glucose using tert-butoxyapatite, a heterogeneous catalyst. The tert-butoxyapatite catalyst was prepared and characterized by several techniques, such as XRD, SEM, TEM, EDS, elemental mapping HR-TEM, N2-adsorption/desorption, XPS, and FT-IR. Several parameters were studied, such as temperature, catalyst loading, and glucose concentration. The tert-butoxyapatite catalyst having both acidic and basic sites gave a maximum glucose conversion of 87\% with a 48\% yield of HMF at 160 degrees C using 20 wt\% catalyst in 12 h. Reusability studies of the catalyst are also presented.

}, issn = {1477-9226}, doi = {10.1039/d5dt01450f}, author = {Kulkarni, Hemant S. and Kamble, Paresh A. and Vinod, Chathakudath P. and Rathod, Virendra K. and Kantam, Mannepalli Lakshmi} } @article {49696, title = {Synthesis of glycolic acid from glyoxal by using hydrotalcite catalyst and kinetic studies}, journal = {ChemCatChem}, volume = {17}, year = {2025}, month = {JUN}, type = {Article}, abstract = {

In this work, Mg-Al hydrotalcite catalysts with different molar ratios were prepared using the co-precipitation method for the synthesis of glycolic acid (GA) from glyoxal. Various reaction parameters such as catalyst molar ratio, time, temperature, catalyst loading, and catalyst poisoning were studied and optimized for better conversion of glyoxal selectively to glycolic acid. Hydrotalcite catalyst with a 2:1 molar ratio of Mg: Al gives 98\% conversion of glyoxal with 96\% selectivity of glycolic acid at 100 degrees C temperature, 40\% catalyst loading, and water as solvent in 8 h. Different characterization methods were used such as XRD, XPS, SEM-EDX, nitrogen adsorption desorption, and CO2-TPD for hydrotalcite catalyst. A kinetic study was also performed to observe the reaction order and activation energy required for the reaction.

}, keywords = {Glycolic acid, Glyoxal, hydrotalcite, kinetics}, issn = {1867-3880}, doi = {10.1002/cctc.202500321}, author = {Pandya, Harmitkumar N. and Kamble, Paresh A. and Vinod, Chathakudath P. and Rathod, Virendra and Kantam, Mannepalli Lakshmi} } @article {49855, title = {W/HAP catalyzed terpenic alcohols oxidation: kinetic studies}, journal = {Reaction Chemistry \& Engineering}, volume = {10}, year = {2025}, month = {OCT }, pages = {2696-2710}, type = {Article}, abstract = {

The selective oxidation of natural alcohols into carbonyl derivatives is a pivotal transformation in synthetic organic chemistry and industrial applications. This study focuses on the oxidation of borneol, a bicyclic secondary terpenic alcohol, into camphor using a tungsten-exchanged hydroxyapatite (W/HAP) catalyst and hydrogen peroxide as a green oxidant. Hydroxyapatite was synthesized via co-precipitation and functionalized with sodium tungstate to create the W/HAP catalyst, which was characterized using techniques such as SEM, EDS, TPD, XPS, and N2 adsorption-desorption to evaluate its surface morphology, porosity, and chemical composition. Oxidation reactions were conducted under optimized conditions, employing dimethylacetamide (DMA) as a solvent to achieve maximum conversion and selectivity. The W/HAP catalyst demonstrated superior performance, achieving nearly 99\% conversion of borneol with 100\% selectivity for camphor. Reaction parameters, including temperature, reactant stoichiometry, solvent choice, and catalyst loading, were systematically investigated. Higher reaction temperatures and oxidant concentrations favoured rapid conversion while maintaining high selectivity. Solvent effects revealed that DMA stabilized peroxo-tungstate intermediates, enhancing reaction efficiency compared to other solvents. Kinetic studies confirmed a first-order reaction mechanism with respect to borneol, and the activation energy was determined to be 44.23 kJ mol-1, highlighting the catalytic efficiency of W/HAP. Reusability tests confirmed the stability of the W/HAP catalyst over multiple cycles with minimal tungsten leaching. The methodology was extended to other terpenic alcohols, with varying degrees of success, emphasizing the substrate-specific activity of the catalyst. This work underscores the potential of tungsten-based heterogeneous catalysts in sustainable alcohol oxidation and highlights the industrial relevance of camphor synthesis as a renewable and eco-friendly approach to produce fine chemicals, fragrances, and pharmaceuticals.

}, issn = {2058-9883}, doi = {10.1039/d5re00132c}, author = {Poman, Aishwarya and Kamble, Paresh and Vinod, Chathakudath P. and Rathod, Virendra and Kantam, Mannepalli Lakshmi} }