@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} }