@article {46147, title = {Epoxidation of karanja (Millettia pinnata) oil methyl esters in the presence of hydrogen peroxide over a simple niobium-containing catalyst}, journal = {Catalysts}, volume = {9}, year = {2019}, month = {APR}, pages = {344}, type = {Article}, abstract = {

The synthesis, characterization and catalytic performance of a conceptually simple, novel NbOx-SiO2 catalyst are here described. The niobium(V)-silica catalyst was prepared starting from cheap and viable reactants, by alkaline deposition of NH4Nb(C2O4)(2)H2O in the presence of fructose as a stabilizer and subsequent calcination. The NbOx-SiO2 solid (0.95 Nb wt.\%) was tested in the liquid-phase epoxidation with aqueous hydrogen peroxide of methyl oleate, as a model substrate. It was then tested in the epoxidation of a mixture of methyl esters (FAMEs) obtained by transesterification with methanol and purification of karanja oil, extracted from the autochthonous Indian variety of Millettia pinnata tree. The catalyst showed a promising performance in terms of methyl oleate conversion (up to 75\%) and selectivity to epoxide (up to 82\%). It was then tested on the FAME mixture from karanja oil, where interesting conversion values were attained (up to 70\%), although with lower selectivities and yields to the mixture of desired epoxidized FAMEs. The solid withstood four catalytic cycles overall, during which a non-negligible surface reorganization of the Nb(V) sites was observed. However, this restructuring did not negatively affect the performance of the catalysts in terms of conversion or selectivity.

}, keywords = {epoxidation, fatty acid methyl esters, heterogeneous catalysis, Hydrogen peroxide, karanja oil, mesoporous silica catalyst, Millettia pinnata, niobium catalysts}, issn = {2073-4344}, doi = {10.3390/catal9040344}, author = {Scotti, Nicola and Ravasio, Nicoletta and Evangelisti, Claudio and Psaro, Rinaldo and Penso, Michele and Niphadkar, Prashant S. and Bokade, Vijay V. and Guidotti, Matteo} }